爆轰波沿炸药传播的（）称为爆速。 A.曲线速度 B.折线速度 C.波浪线速度 D.直

下列语句排序最恰当的一项是[ ]

①他于是放下自己的这块肉，冲过去抢那块。

②那一块没捞到，因为本来就没有，这一块也被流水冲走了。

③结果，两块肉都没有了。

④狗衔着一块肉过河，望见自己在水里的影子。

⑤以为是另外一只狗衔着一块更大的肉。

A．④①⑤③②

B．④③②①⑤

C．④⑤③②①

D．④⑤①③②

改写句子。

1. Being ill, he didn't come to Mary's birthday party. (改为含有状语从句的复合句)

    ___________________________, he didn't come to Mary's birthday party.

2. The bridge which was built in 1888 is now under repairs. (改为简单句)

    ___________________________ is now under repairs.

3. He is said to have passed the driving test. (改为含有主语从句的复合句)

    ___________________________ he has passed the driving test.

4. Although he is still poor, he has already grasped two foreign languages. (改为倒装句)

    ___________________________, he has already grasped two foreign languages.

5. He didn't go to school until he was ten years old. (改为强调句)

    ____________________________________________ he went to school.

6. I saw several houses with mosaic floor and wall paintings. (画线部分改写成定语从句)

    ____________________________________________

7. With the help of the kind old man, we arrived at the remote village before lunchtime. (用with复合结构做).

    ___________________________, we arrived at the remote village before lunchtime.

8. "Please don't open the window." said Jack politely to his classmate.

    Jack asked his classmate politely _________________________ (间接引语).

9. Time permitting, we can have a walk around the playground after supper. (画线部分改写成状语从句)

    ___________________________, we can have a walk around the playground after supper.

10. When we see from the hilltop, we can find the city more beautiful. (画线部分改写成分词作状语)

     ___________________________, we can find the city more beautiful.

乒乓球被誉为我国的“国球”，其直径约为40mm，质量约为（　　）

A．3g

B．30g

C．300g

D．3000g

甲亢术后呼吸困难多发生于术后（）

A.6小时以内

B.12小时以内

C.24小时以内

D.48小时以内

E.72小时以内

如图所示为一个草原生态系统中的食物网简图，请据图分析并回答：

兔在该食物网中属第（）营养级。