AB为斜面,倾角为30°,小球从A点以初速度V0水平抛出,恰好落到B点,则A、B

题型:填空题

问题:

AB为斜面,倾角为30°,小球从A点以初速度V0水平抛出,恰好落到B点,则A、B间的距离______,物体在空中飞行的时间______,到达B点的速度______.

考点:平抛运动
题型:填空题

一种牙膏的管口直径是6毫米,小红每次刷牙都挤1厘米长的牙膏,一支这种牙膏可挤40次.现在,这种牙膏改变了包装,将管口直径改为8毫米,但小红还是习惯每次挤出1厘米长的牙膏.新包装的这种牙膏最多能挤多少次?

题型:填空题

为了保证能长时间潜航,在潜水艇里装备氧气再生装置.有以下几种制氧气的方法:  

①加热高锰酸钾制氧气;  

②通电分解水 ;  

③过氧化钠固体与二氧化碳反应:(过氧化钠+二氧化碳→碳酸钠+氧气)   

请你回答下列问题:  

(1)你认为最适合潜水艇里制取氧气的方法是____;  

(2)与其他两种方法相比较,这种最适合的方法的两条优点是什么?

题型:填空题

医学伦理学原则不包括().

A.公正原则

B.有利原则

C.不伤害原则

D.生命价值原则

E.尊重原则

题型:填空题

阅读理解。

     A poor chimney-sweeper, who had not enough money to buy a meal, stopped one hot summer day at noon

before an eating-house, and remained regaling (享受) his nose with the smell of the victuals. The master of the

shop told him several times to go away, but the sweeper could not leave savory smell, though unable to purchase

the taste of the food. At last the cook came out of the shop, and taking hold of the sweeper, declared that, as he

had been feeding upon the smell of his victuals, he should not go away without paying half the price of a dinner.

The poor fellow said that he neither could nor would pay, and that he would ask the first person who should

pass, whether it was an unreasonable and unjust demand.

     The case was referred to a policeman, who happened to pass at that moment. He said to the sweeper:"As you

have been feasting one of your senses with the odor (气味) of this man's meat, it is but just you should make

him some recompense; therefore you shall, in your turn, regale one of his senses, which seems to be more

insatiable than your appetite. How much money do you have?"

     "I have but two pence in all the world, sir, and I must buy me some bread."

     "Never mind," answered the officer. "Take your two pence between your hands; now rattle them loudly."

     The sweeper did so, and the officer, turning to the cook, said, "Now, sir, I think he has paid you: the smell

of your victuals regaled his nostrils; the sound of his money has tickled your ears."

     This decision gave more satisfaction to the bystanders than to the cook, but it was the only payment he could

obtain.

1. The sweeper stopped one hot summer day at noon before an eating-house, because ____.

A. he wanted to regale his nose with the smell of the victuals

B. he was hungry and he wanted to have dinner

C. he was hungry but he had no enough money to buy a meal

D. he wanted to smell if the food was delicious

2. The cook's demand that the sweeper should pay half the price of a dinner was obviously ____.

 A. reasonable

B. not fair

C. logical

D. proper

3. We infer that the way that the policeman settled the problem was ____.

A. foolish

B. kind

C. clever

D. stupid

4. The passage implied, but didn't say clearly that ____.

A. it's a pity that the cook did not get what he wanted

B. the master of the shop and the cook were cool-hearted

C. the cook was cruel

D. the sweeper got what he wanted

题型:填空题

土壤的环境条件较为稳定,所以根系的生长量是均衡的。

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