对支撑剂性能要求叙述错误的是（）。A.强度大、分选好、圆球度好 B.粒径较大、机械杂

阅读理解。

     When I was growing up, I had an old neighbor, Dr. Gibbs. He didn't look like any doctor I'd ever known.

He never invited us to play in his yard, but he was a very kind person.

     When Dr. Gibbs wasn't saving lives, he was planting trees. He owned a large field and wanted to make it

a forest.

     The good doctor had some interesting ideas about planting trees. He never watered his new trees. Once I

asked why. He said that watering plants spoiled them, and that if you watered them, each baby tree would

grow weaker and weaker, so you had to make things difficult for them and pick out the weaker trees early

on.

     He talked about how watering trees made for shallow (浅的) roots, and how trees that weren't watered

had to grow deep roots in search of water under the earth by themselves. Deep roots were very important.

     So he never watered his trees. He'd planted an oak and, instead of watering it every morning, he'd beat it

with a rolled-up newspaper. I asked him why he did that, and he said it was to get the tree's attention.

     Dr. Gibbs died several years after I left home. Every now and then, I walked by his house and looked at

the trees that I watched him plant about twenty-five years ago. They're very big and strong now. I planted

some trees a few years back and carried water to them for a whole summer. After two years of caring too

much, whenever a cold wind blows in, they shake a lot.

     Every night before I go to bed, I check on my two sons. Mostly I pray (祈祷) that their lives will be easy.

But lately I've been thinking that it's time to change my prayer. I know my children are going to face difficulties.

There's always a cold wind blowing somewhere, so what we need to do is to pray for roots that reach deep

into the brave heart, so when the rains fall and the winds blow, we could face it strongly and won't be beaten

down.

1. We know from the reading the doctor ______.

A. didn't know how to plant trees at all

B. wasn't good at his own medical job

C. had his own ways of planting trees

D. had nothing to do but plant trees

2. When Dr. Gibbs said "... pick out the weaker trees early on.", he meant that ______.

A. some weak trees would be easily found out at the beginning

B. he would choose the weak trees to w ater earlier

C. the weak trees would be sent to his patients later

D. he would not plant weak trees so early anymore

3. The passage tells us that the writer ______.

A. should beat his trees with a rolled-up newspaper

B. didn't often water his trees

C. didn't have a large field

D. took too much care of his trees

4. The writer wants to change his prayer, hoping that ______.

A. his trees will be stronger than Dr. Gibbs'

B. his trees will not be beaten down

C. his sons will be better at planting trees

D. his sons will be able to face difficulties

5. Which can be the best title of the reading?

A. Watering Trees

B. Growing Roots

C. Doctor and his Neighbor

D. Father and his Children

社会必要劳动时间，是指在现有的社会正常的生产条件下，在社会平均的劳动熟练程度和劳动强度下，制造某种商品所需要的劳动时间。这里的“现有的社会正常的生产条件”是指

A．当时在一定生产部门里，生产规模的大小

B．当时在一定生产部门里，所有产品的平均生产条件

C．当时在全部生产部门里，绝大部分产品的生产条件

D．当时在一定生产部门里，绝大部分产品的生产条件

木工师傅做完门框后为防止变形，通常在角上打一根木条，这种做法的根据是（    ）。

MicroATX与ATX主板外形规格的主要区别是（）

A.较小的外形尺寸

B.不同的部件布局

C.较少的I/O扩展插槽

D.较小的电源选择

由于作物根系具有（），所以经常在苗期控制灌水，实行蹲苗，可促使根系下扎。