Reading answers to Why Can t Trees Grow Infinitely Tall Looking back at Qian Xuesen Reading aloud

Looking back at Qian Xuesen.

1.He goes to the restaurant to eat in a neatly dressed and shows respect for others; His manuscripts are like works of art, showing his scientific rigor; His academic performance in China and his study and work in the United States.

2.(1) Qian Xuesen's manuscript is neat and meticulous.

2) Qian Xuesen solves problems and strives for excellence.

3.For the comparison of his spirit.

4.(1) A person's academic performance does not represent his success, a person wants to succeed, must have a diligent spirit, therefore, each of us can succeed, but we must work diligently (2) never satisfied, scientific exploration never ending the spirit.

5 This question is an open-ended example 1: The small and big techniques are written about Qian Xuesen's small things, but from a small aspect, it shows the sublime realm of the characters This is the way to write, with a drop of water to reflect the brilliance of the sun, it is worth learning Example 2: The combination of direct description and indirect description of the technique works has both a direct description of Qian Xuesen, and other people's views on it, such as:

Appreciating his manuscripts, the memories of his alumni and students, and showing his studies and work, is more realistic and convincing, combining direct and indirect descriptions, expanding the breadth and depth of the narrative and making the characters more vivid (choose one side).

20 (1) In the age of the rapidly developing bubble, it is very difficult to remember what is meaningful. (2 points) (2) Reading aloud is a beautiful process, which will arouse emotion, association and memory, and give people strength. (2 points).

21 (1) I write a good article and always want to read it to others. (2 points) (2) I found a good book and always wanted to move others with me. (2 points).

22 No reader (1 point) No listener (1 point).

23 d (3 points).

Little Dolma in the snow.

12.(1) The delicate and vivid description reflects the process of change in the little girl's heart. "Eyes lit up" because she liked and needed the delicately packaged foods, and "then shook her head" because she wanted to save them for those who needed them more. (2 points).

2) Little Dolma wants to express an indescribable gratitude in her own way. (2 points).

13.It's not the same. Little Dolma said "thank you" to express her gratitude to the rescuers. "I" said "thank you" to Xiao Zhuoma because "I" was moved by Xiao Zhuoma's infatuation and decision to express my heartfelt admiration. (3 points).

14."The figure of Little Dolma in the snow, like a cluster of scarlet bonfires" corresponds to the first paragraph. At the same time, it also uses figurative rhetorical devices.

It highlights the warmth and touching that Little Dolma brings to people, and sublimates the theme. (3 points).

15.Little Dolma is an innocent, calm, mature, determined, tenacious, and sensible little girl who knows how to repay her kindness. (3 points).

16.Omit (requirement: the content should express concern and encouragement) (2 points).

Nanqiao is a classmate in the second year of junior high school.

Looking back at Qian Xuesen.

1).Dressed neatly to go to dinner shows Qian Xuesen's respect for others.

2).The manuscript is like a work of art, showing Qian Xuesen's meticulous work.

3).Achievements and work show Qian Xuesen's seriousness in his work.

2.It shows that a person's success or failure is not absolutely proportional to the test score.

3.Side description: Only then did I realize that Chinese students work harder than Jewish students. Highlight Qian Xuesen's hard work.

4.Patriotism.

Read aloud. 1.Many things are frothy, and it is very difficult for a person to remember anything.

2.When you write a good article, you will want to read it to others, and when you find a good book, you will want others to be moved with you.

3.There is no reader, no listener.

Election turmoil. 1.Jarry is enthusiastic, intelligent, has a sense of justice and a sense of responsibility.

2.Because being a Chinese kid has a lot to worry about.

3.Zealous and responsible.

4.Free to play.

The rest are not posted. How many classes are you in, please?

The main reason why trees cannot grow indefinitely is the gravitational pull of the earth, which is gravity. The presence of gravity severely hinders the smooth transport of water within the tree, especially to the very high tops of the trees. As you know, plants absorb water from their roots and transport it to the top by the power generated by evaporating water from the stomata on the surface of the leaves.

Therefore, measuring the tension of water in the top tissues of trees has become an important basis for determining the height limit of trees. Dr. George Koch of Arizona State University was the first to climb five of the world's tallest trees to measure water transport, the tallest of which is the giant sequoia, which grows in California, USA, known as the "world's tallest tree", and the tree is more than 30 stories tall. At the top of these trees, they found the leaves that were in a state of dehydration.

These leaves are similar to those of plants grown in extremely arid deserts. Despite the abundance of moisture in the soil, trees must overcome gravity and intraductal friction to transport water from the roots through the xylem to the leaves at the top of the tree. The study found that it took up to 24 days for water to be transported from the roots of these trees to the top.

Scientists have concluded that the limit of the height of trees on Earth is 122-130 meters, beyond which it is difficult for water to reach the top of the tree, and photosynthesis on the top of the tree cannot take place.

From the perspective of photosynthesis, carbon dioxide concentration is also an important reason for the growth and height of trees. Carbon dioxide is denser than in the air, so as the altitude increases, the concentration of carbon dioxide in the atmosphere decreases, and photosynthesis at the top of the tree is limited, so the tree will not be able to continue to grow taller.

From the perspective of hormone regulation, the concentration of auxin limits the infinite growth and height of trees. Because the growth of side branches can lead to a decrease in the concentration of auxin in the top branches of the tree, thus inhibiting the growth of the top branches of the tree.

The inability of trees to grow indefinitely is also the result of natural selection. Think about it, if trees can grow indefinitely high in the sky, then such trees are more likely to be struck by wind and lightning. As a result, the height of a tree is limited in its adaptation to the external environment.

According to Darwin's theory of "natural selection", trees are the best at adapting to their environment. Think about it, if the trees grow indefinitely, it will attract disasters such as wind and lightning, and will also cause insufficient supply of sunlight, oxygen, water, nutrients, and temperature. Self-support capacity is also a big problem.

For example, if the length and diameter of a tree increase to the same multiple, and the pressure resistance of the trunk is proportional to the cross-sectional area, i.e., it can only increase by a factor of 10,000, so the load is 100 times greater per square centimeter of cross-sectional area. Obviously, if the geometry of the trunk is always similar to the original, the tree will be crushed by its own weight. If a tall tree wants to remain intact, its thickness should have a greater ratio of height than that of a lower tree.

However, as a result of thickening, the load on the lower part of the tree will be increased. As a result, the height of a tree is limited in its adaptation to the external environment. Of course, the growth of lateral branches also inhibits the growth of the apical branches.

Why can't trees be without?

Bai limit du grow taller? Stress & Zhi Adaptation. Why can't the world's trees, including the 132-meter-tall eucalyptus back and the 115-meter-tall sequoia, grow indefinitely taller?

According to Darwin's theory of natural selection. Trees are the best at adapting to their environment. Think about it, if the trees grow indefinitely, it will attract disasters such as wind and thunder, and will also cause insufficient supply of sunlight, oxygen, water, nutrients, and be limited by temperature.

Self-support capacity is also a big problem. The height of trees is limited in the process of adapting to the external environment. Of course, the growth of lateral branches also inhibits the growth of the apical branches.

1.The presence of gravity hinders the smooth transport of water within the tree; effects of carbon dioxide concentration; Limitation of the concentration of auxin; The result of natural selection.

2.The power generated by the evaporation of water from the stomata on the surface of the leaves absorbs water from the roots and transports it to the top.

3.Examples of sub-column numbers.

4.Gravity, catheter friction obstruction.