I don t ask for sixth grade science questions

The first question does not provide an optional answer It is too arbitrary to answer 2: Survival struggle Species with strong competitiveness Species with weak competitiveness 3: False or false question Because the variation of species is not directed Only species suitable for the environment can survive Species with short necks are starved to death because they cannot survive Species that mutate in the direction of long necks are more adapted to the environment and are preserved As stated in the second question 4:

Grass Cow People Q&A Questions: The first question is also very general If the textbook has the original words, follow the textbook This is not good If not, 1 Pay attention to adjust your emotions, behavior, etc. Two:

In order to use stripes to confuse predators when living in groups, so that they cannot quickly lock on to a target to capture, so that the probability of catching their own ** decreases and thus improves survivability Three: friction when rubbing hands produces internal energy (heat energy) Analysis and explanation question One: The popularity of family cars will increase energy consumption, increase the degree of environmental pollution, and increase their own financial burden, so if it is not very necessary, I think it is still not advisable to use it universally

People pollute the environment and consume resources in their pursuit of wealth. We have lost non-renewable resources, lost the good environment of the past, and the environment has deteriorated, and our physical fitness will also decline.

Fill in the blank: A 1 Metabolism 2? 3？

4？21 Struggle for Survival 2 Species with Weak Competitiveness Judgment: 1 Pair Grass - Cattle - People Questions and Answers:

1. Pay attention to adjusting your emotions, behavior, etc. 2 Streak effect: It is the result of environmental selection, mainly to interfere with the sight of carnivores and improve their survival chances. 3. When rubbing hands, kinetic energy is converted into heat energy, which heats up the hands.

4 Family cars, while providing convenience for their own families, also pollute the air. Therefore, I personally believe that family cars should not be widely used. While the five people continue to get rich, they continue to use all kinds of resources on the earth, so that some resources are facing depletion.

Human beings are also constantly polluting the environment, which makes the earth's environment worse and worse. At the same time, human beings are constantly trying all kinds of delicacies from the mountains and seas, but lack of exercise, resulting in worse and worse physical condition.

Solution 1: Let the proportion of sugar A be x, then the sugar B is 1-x and there are 3 x+ to solve the equation to obtain x=

Therefore, the mass ratio of the two sugars is 3. Solution 2: Yuan, each kilogram of B sugar should be higher than the average price, and each kilogram of A sugar should be lower than the average price of 3 yuan.

5 kilograms of B sugar can be taken out to fill the 3 yuan per kilogram of A sugar, so the average price of every 5 kg of B sugar and each kilogram of A sugar is mixed with Yuan.

Thus, the weight ratio of the two sugars is 1:3

The equation is (:(3

I do have a sixth-grade math problem, which is kind of interesting.

There are 7 numbers arranged in order from small to large, and their average is 40, the average of the first 4 numbers of this group of numbers is 37, and the average of the last 4 numbers is 44, what is the median of these 7 numbers?

Generally speaking, the devices that can save us effort or convenience are called levers, and the most common ones are doorknobs, jacks, wrenches, etc.

Archimedes said that as long as you give me a fulcrum in the universe, I can use a long stick to pry up against the earth. This is talking about the lever as a machine.

To raise a relatively light flag, we only need to use a single pulley, and to lift a few hundred kilograms or more, we use a pulley set or lever.

The axle is one of the most used machines, and we use force on the axle to save effort, but sometimes we also use force on the shaft, which is more laborious.

6. The production of electromagnets must have three parts: power supply, coil and iron core, which produce magnetism when it is energized, and after the power is off, the magnetism disappears.

7. Organisms on the earth are slowly changing, and the reasons are the selection of the environment and the selection of genetic mutations.

8. The energy possessed by objects related to motion is called kinetic energy, and the energy stored in fuel, food and some chemicals is called chemical energy.

10. Commonly used power generation methods include hydropower, thermal power, nuclear energy, wind power, etc.

Second, judgment. 1,5,6 False, Others True.

III, 1 a

2a3a4c5b

The fourth question is too messy.

The first three can also be connected.

Birds - feathers.

Mammals - viviparous.

Insects - three pairs of legs.

1. Now you want to make an electromagnet to make it very magnetic, how do you think about it?

Increase the current, wind the coil more, increase the diameter of the coil, increase the volume of the core.

Is this a 6th grade question?

Only partially.

1.Iron and aluminum will sink to the bottom of the water, so their volume is all immersed in water, and the density of iron is greater than aluminum, in the case of equal mass, the volume of aluminum is large, so the buoyancy of aluminum is large, and the spring scale is small.

Cattle and cattle. 3.Less than, less than.

I don't know if it's right.