关于肾病综合征的主要临床特征，以下哪项最正确（）。 A.大量蛋白尿，高血压，血尿，低

某物理课外活动小组在老师的指导下做了水火箭升空实验。

实验器材有：饮料瓶、气筒、自行车气门、铁丝、橡皮塞、水等。水火箭构造如图所示。根据老师的介绍，同学们了解到水火箭升空原理如下：在瓶中装适量的水，塞好瓶塞后放在发射架上。用气筒向瓶内打气，瓶内上方气体压强达到一定程度，高压气体将水和橡皮塞从瓶口压出，利用水的反冲作用把瓶推向高空。

（1）水火箭升空原理可利用我们所学过的__________知识来解释。从能量转化角度来看，水火箭的动能是由________能转化来的。

（2）实验后小明提出了问题：水火箭上升高度与什么因素有关呢？

小明猜想：可能与瓶中气体的压强有关；

小华猜想：可能与瓶中水的体积有关；

小军猜想……

你认为影响因素还有___________。（写出一点即可）

（3）实验小组通过试验发现，瓶塞插入深度不同，瓶塞被冲出前用气筒充气次数不同（设充一次气气量相同），他们选用同一可乐瓶，瓶中水量为200ml。通过站在不同楼层观察员目测进行数据记录。考虑到安全做了三次，实验结果如下：

这可验证水火箭上升高度与_________有关的猜想是正确的。

（4）为了验证小华的猜想，他们在实验中应该保持______不变，这是应用了_________法使研究过程简洁明了。

生物体细胞中的“能量工厂”是（        ）。

Generations of Americans have been brought up to believe that a good breakfast is essential to one’s life. Eating breakfast at the start of the day, we have been told, and told again, is as necessary as putting gasoline in the family car before starting a trip.

But for many people, the thought of food as the first thing in the morning is never a pleasure. So in spite of all the efforts, they still take no breakfast. Between 1977 and 1983, the latest year for which figures could be obtained(可获得的), the number of people who didn’t have breakfast increased by 33%—from 8.8 million to 11.7 million—according to the Chicago-based Market Research Corporation of America.

For those who dislike eating breakfast, however, there is some good news. Several studies in the last few years have shown that, for grown-ups especially, there may be nothing wrong with omitting(省略) breakfast. “Going without breakfast does not affect work,” said Arnold E. Bender, former professor of nutrition at Queen Elizabeth College in London, “nor does giving people breakfast improve work.”

Scientific evidence linking breakfast to better health or better work is surprisingly inadequate(不适当), and most of the recent work involves(涉及) children, not grown-ups. “The literature,” says one researcher, Dr Earnest Polite at the University of Texas, “is poor.”

小题1:The main idea of the passage is _______.

A．breakfast has nothing to do with people’s health

B．a good breakfast used to be important to us

C．breakfast is not as important to us as gasoline to a car

D．breakfast is not as important as we thought before小题2:For those who do not take breakfast, the good news is that _______.

A．several studies have been done in the past few years

B．the omission of breakfast does no harm to one’s health

C．grown-ups have especially made studies in this field

D．eating little in the morning is good for health小题3:The underlined part “nor does giving people breakfast improve work” means _______.

A．people without breakfast can improve their work

B．not giving people breakfast improves work

C．having breakfast does not improve work, either

D．people having breakfast do improve their work, too小题4:The word "literature" in the last sentence refers to _______.

A．stories, poems, play, etc

B．written works on a particular subject

C．any printed material

D．the modern literature of America小题5:What is implied but not stated by the author is that _______.

A．breakfast does not affect work

B．Dr Polite works at an institution of higher learning

C．not eating breakfast might affect the health of children

D．Professor Bender once taught college courses in nutrition in London

机器周期性速度波动采用（）调节，非周期性速度波动采用（）调节。

如何调节横墙温度？