切片时，蜡片出现薄厚不匀现象的原因是（） A.组织块过硬 B.切片刀不够锋利 C.组

从“+、-、×、÷、( )”中，选出适当的符号，填入下列算式适当的地方，使结果等于已知数。

（1）4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4=1991 ；

（2）4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4=1997 。

求长方形的周长必须知道（    ）和（    ），求正方形的周长必须知道（    ）。

“Old wives tales” are beliefs lasting for many generations. For example, most of us remember our parents’ telling us to eat more of certain foods or not to do certain things. Is there any truth in these teachings? Some of them agree with present medical thinking, but others have not passed the test of time.

Did your mother ever tell you to eat your carrots because they are good for your eyes? Scientists now report that eating carrots can help prevent a serious eye disease called macular degeneration. Eating just one carrot a day can reduce the possibility of getting this disease by 40%. Garlic is good for you, too. It can kill the type of virus that causes colds.

Unfortunately, not all of Mom’ s advice passed the test of medical studies. For example, generations of children have been told not to go swimming within an hour after eating. But research suggests that there is no danger in doing so. Do sweets cause tooth problems? Well, yes. However, sticky sweets made with grains tend to cause more problems than sweets made with simple sugars.

Even though science can tell us that some of our traditional beliefs don’t hold water, there is still a lot of truth in the old wives’ tales. After all, much of this knowledge has been accumulated from thousands of years of experience in family health care. We should respect this body of knowledge even as we search for clear scientific support to prove it true or false.

小题1:Which of the following is TRUE according to the test?

A．Eating garlic is good for our eyes.

B．Sticky sweets are damaging our teeth.

C．Swimming after a meal is dangerous.

D．Carrots prevent people from catching colds.小题2: The phrase “hold water” in the last paragraph most probably means”_____”.

A．to be believable

B．to be valuable

C．to be admirable

D．to be suitable小题3:What is the author’s attitude toward “old wives tales” in the text?

A．Subjective

B．Objective

C．Dissatisfied

D．Curious

小兰同学通过观察身边的一些现象，如图22所示，一辆小车静止在长木板上，给小车一个水平力F，小车便沿力F的方向运动起来；手拿一小木块在空中由静止释放，小木块便在重力的作用下，沿重力的方向竖直向下运动。于是小兰得出一个结论：物体的运动方向一定与物体所受外力的合力方向一致。请你仅利用如图22所示的器材，设计一个小实验，说明小兰的结论是不正确的。请写出主要实验步骤和实验现象，并简要分析小兰的结论是不正确的。

下列不属于配送成本的是（）。

A.配送运输费用

B.配装费用

C.信息流通费用

D.流通加工费用