关于可乐定，叙述正确的有（）。 A.选择性α1-受体激动剂 B.具有降压作用 C.具

根据第一个句子的意思，完成第二个句子，每个空格只准填一个单词。

1. The newspaper says the price of houses will continue to rise.

    It _______ _______ that the price of houses will continue to _______ _______.

2. We don't have to leave so early.

    There is _______ _______ _______ _______ to leave so early.

3. I visited a specific house last Sunday. I will remember it forever.

    I will _______ remember the specific house _______ _______ _______ last Sunday.

4. His Chinese has improved a lot since he came to China.

    He has _______ great _______ in Chinese since he came to China.

5. I expect to go to your party.

    I am _______ _______ _______ _______ to your party.

袋子里有同样大小的红球和黄球各5个。要想摸出的球一定是2个同色的，最少要摸出（    ）个球。

医学文献将海拔多少米以上的地区定为高原()

A．2000m

B．2500m

C．3000m

D．3500m

E．5800m

牵引术助产，胎儿前腿尚未进入骨盆腔时，牵引的方向应为______。

A．向上向后
B．水平向后拉
C．略向下拉
D．向后向下
E．向前向上

无线电发射机的主要作用是什么？