小明在玻璃杯内盛满水,杯口盖上一张硬纸片(不留空气),然后托住纸片,将杯子倒置或倾斜,水都不流出,纸片也不掉下(如图所示)。对整个探究活动的分析正确的是( )
A:探究的问题:大气压强有多大
B:探究的假设:大气对各个方向都有压强
C:探究的目的:研究水的重力与大气压力的关系
D:探究的结论:大气向各个方向的压强相等
If you want to be a better reader,what should you know about the speed(速度)of reading? Some people read very quickly,when others read very slowly. But which one is better? The quick reader may be a good reader when he reads a story-book for fun. But he may not be able to slow down to read instructions(说明书) carefully. The slow reader may be a good reader. But he may spend too much time reading a story for fun. So the reader who reads everything quickly or the one who reads everything slowly isn't really a good reader. Here are four things to remember about the speed of reading. Knowing why you are reading will help you to know whether(是否) to read quickly or slowly.Some things should be read slowly throughout. Examples(例子)are instructions for making or doing something. Math books,science and story-books are full of important information. You must read these things slowly to understand and remember every important idea. Some things should be read quickly throughout. Examples are stories for enjoyment,letters from friends,and some news from newspapers.In some of your reading,you must change your speed from fast to slow and slow to fast. You will need to read some pages quickly and then slow down and do more careful reading when you come to important ideas.