先导化合物是指A．很理想的临床用药 B．新化合物 C．具有某种

搜题请搜索小程序“爱下问搜题”

问题单项选择题

先导化合物是指

A．很理想的临床用药

B．新化合物

C．具有某种生物活性的化学结构，可作为结构修饰和结构改造的化合物

D．不具有生物活性的化合物

E．临床上已淘汰的药物

答案

参考答案：C

填空题

根据句意，用括号中所给单词的正确形式填空，每空一词。

1. So far, I haven't made a (decide) about where to go for the coming summer holidays.

2. This year it has rained so (heavy) in South China that lots of problems are caused.

3. When we walked past the playground yesterday, we found him (lie) on the grass, enjoying

the sunset.

4. Jack is busy preparing for a party to celebrate his sister's (twelve) birthday. He wants to give

her a big surprise.

5. — On April 14th, an earthquake hit Yushu and destroyed its (beautiful) completely.

— It's a great pity.

单项选择题

引起前置胎盘最可能的因素是()

A．母儿血型不和

B．子宫内膜病变

C．黄体功能不全

D．孕妇血管病变

E．子宫肌纤维发育不良