若椭圆的左右焦点分别为F1，F2，线段F1F2被抛物线y2=2bx的焦点分成5:3的

阅读理解。

     It was getting late. There was no noise in the forest. We could only hear the birds singing. And then,

a bear-a big brown bear-came into the forest.

     The bear stopped under a tall tree. He was very hungry. He looked up into the tree. There in the nut

tree was his supper-a supper of nice nuts. But the nuts were high up in the tree. The hungry bear could

not reach them. But he knew how to get his supper. He climbed up the tree.

     Up and up he climbed. He climbed onto a big branch of the tree. He sat there and then shook (摇)

the branch again and again. At last the branch broke. The brown bear fell down with the branch and nuts.

     The bear sat up and looked around. With his big paws he picked up the nuts and ate them up.

1. How did the brown bear get his supper?

A. He climbed up the tree and ate the nuts there.

B. He shook the apples off a tree and ate them.

C. He picked up the nuts on the ground and ate them.

D. He fell down with the branch of the tree. Then he took the nuts and ate them.

2. The bear was     __    .

A. black                                  

B. brown

C. black and white                          

D. brown and black

3. Where did the bear eat the nuts?

A. in a forest.                            

B. outside the forest.

C. near a forest.                          

D. in front of the forest.

造成再生障碍性贫血最主要的原因是

A．造血原料不足
B．长期营养不良
C．脾功能亢进
D．骨髓造血功能衰竭
E．急性大量失血

在甲、乙、丙、丁四个相同的容器中，分别盛有水、盐水、酒精和水银四种液体，把四块质量相同、外形不同的冰块分别放入四个容器中，此时液面高度相同，当冰块融化后，下列叙述正确的是( )。

A．水面高度不变，其他液面都升高
B．酒精液面降低，水面高度不变，盐水和水银液面升高
C．酒精和水面都升高，盐水和水银液面降低
D．水面升高，酒精液面高度不变，盐水和水银液面升高

(三)

第一段中提到“植物生物钟”，第二段提到“植物周期行为”、“生理节律”和“异步个体”。对文中这四个概念的理解，正确的一项是( )

A．四个概念完全相同

B．四个概念各不相同

C．前两个概念相同，后两个概念相同

D．最后一个概念不同于前三个概念

下列宝石在饱和盐酸中悬浮的是（）

A.珍珠

B.琥珀

C.火山玻璃