The quicker the answer, the better, and the quicker the answer, the better

Hydrogen: zinc + dilute sulfuric acid.

Chlorine: manganese dioxide + concentrated hydrochloric acid + heating.

Oxygen: hydrogen peroxide + manganese dioxide or heated solid potassium permanganate.

Ammonia: concentrated sodium hydroxide + ammonium chloride + heating.

Carbon dioxide: calcium carbonate + dilute hydrochloric acid.

Nitrogen dioxide: copper + concentrated nitric acid.

Carbon monoxide: copper + dilute nitric acid.

Sulfur dioxide: concentrated sulfuric acid + sodium sulfite.

In this solution, we use the conclusion that when an object is balanced by only three forces, the lines of action of these three forces must be common or parallel. Proof : Suppose there are two lines of action intersecting and the third line is not this point, then take this point as the benchmark, the moment of the first two forces to this point is zero and the last force is not zero, the resultant moment is not zero, and the object is in equilibrium.

In this problem, the directions of the three forces are obviously not parallel, so they must pass the same point.

I like to copy and be friends with books. Because of the Gower attack.

Kei once said that books are human progress.

The ladder of du.

It taught me wisdom and knowledge; It taught me the principles of being a human being; It taught me to have the courage to admit and correct my mistakes. It taught me to honor my parents, respect my teachers, and be polite to others. He taught me to be honest and trustworthy, and to be consistent with my words and deeds; It taught me to be industrious, courageous, strong, humble, benevolent, ....... It nourishes life and fragrances the soul. In short, in my years of friendship with it, it once took me on a boat to the distant ocean of knowledge, to the island of wisdom.

The origin of the name is misprinted, it should be a vulture: because of the lack of hair on the top of his head, he is called "vulture" by his friends.

Horse: The man named Horse is a boy. It was Qiu Da's youngest son, a very energetic boy, with a large forehead, slightly blushing eyes, slightly yellow eyes, but surprisingly bright, and two front teeth slightly larger.

Sangsang: His father is the headmaster Sancho, so Sangsang is sexual. is the protagonist of the text.

White Sparrow: She has a good voice, not loud, not wide, but as crisp as a silver bell.

Liu Liu: **The younger sister of the protagonist Sangsang (both brother and sister are named after trees).

The specific answer is as follows:

easily

useful

It can be seen from the above answer that the adverb is generally added to the back, and the adjective is added to the adjective, I hope you can understand and grasp it.

Heilongjiang (Hei, Harbin).

Jilin (Jilin, Changchun).

Liaoning (Liaoning, Shenyang).

Hebei (Hebei, Shijiazhuang).

Henan (Henan, Zhengzhou).

Shanxi (Jin, Taiyuan).

Shandong (Shandong, Jinan).

Jiangsu (Suzhou, Nanjing).

Jiangxi (Jiangxi, Nanchang).

Hunan (Xiangzihao, Changsha).

Hubei (Hubei, Wuhan).

Yunnan (Yunnan, Kunming).

Guizhou (Guizhou, Guiyang).

Sichuan Beixian (Shu, Chengdu).

Fujian (Fujian, Fuzhou).

Guangdong (Guangdong, Guangzhou).

Shaanxi (Qin, Shaanxi, Xi'an).

Qinghai (Qinghai, Xining).

Zhejiang (Zhejiang, Hangzhou).

Gansu (Gansu, Lanzhou).

Anhui (Anhui, Hefei).

Taiwan (Taiwan, Taipei).

Hainan (Qiong, Haikou), Wangoh

The library has a detailed explanation and answer to the detailed hail survey, see question 19.

1. The particle point m is relative to the wooden board, and due to the inertia, the friction force f= is applied to the forward friction, and the relative wooden board is decelerated in motion.

The particle m is only subjected to f friction force = ma has a = 4 1 = 4m s and the direction is opposite to the direction of movement of the plank. There is s=1 2at There is t=, and the open root number with t= has t=.

2.The moment the particle leaves the board, it is relative to the desktop v=at=2m s. The particle is decelerated by friction on the table, and there is f friction = ma1

If there is a1=, the sliding time of the particle on the desktop after leaving the plank is t=1s, and the displacement of the particle after leaving the plank is s=1m, then the displacement of the plank and the particle running together is s=, and the running time is a2=4m s and the direction of movement of the plank is the same.

by f=m combined a2

There is a constant force f = (land reform 1 + 1) ridge x4 = 8n.