代理财政授权支付业务的使用对象是（）和预算单位。A.人民银行 B.国库支付局 C.总

The boy was having a class when the earthquake broke out in yushu. He could have been killed if he      with his family.

A．had stayed

B．stayed

C．would stay

D．is to stay

根据句意和首字母或汉语提示完成单词。

1. — How often does Mary exercise? 

    — She exercises t________ a week.

2. — Could I b_______ your bike?

    — Yes. Here's the key.(钥匙)

3. It often rains in s________ China in summer.

4. Here are two _________(薄片) of bread.

5. Her writing __________(习惯) are very good.

6. I was really busy. I spent the w________ morning doing my homework.

7.We must read ____________(说明) before taking medicine.

8. He won first prize in the singing c_________.

9. Her favorite subjects are c____________ and physics.

10. My cousin b_________ a teacher in 2008.

下面为植物组织培养过程流程图解，以下相关叙述不正确的是

A．上述过程中脱分化发生在b步骤，形成愈伤组织，在此过程中植物激素发挥了重要作用

B．再分化发生在d步骤，是愈伤组织重新分化成根或芽等器官的过程

C．从叶组织块到种苗形成的过程说明番茄叶片细胞具有全能性

D．人工种子可以解决有些作物品种繁殖能力差、结子困难或发芽率低等问题

（）不是交流电磁换向阀的缺点。

A．换向冲击较大

B．允许工作频率较低

C．阀芯卡住会烧坏

D．价格相对较高

要实现全面建设小康社会的经济目标，就必须（）

①增强发展协调性，努力实现经济又好又快发展

②转变经济发展方式，建设生态文明

③全面改善人民生活，社会就业更加充分

④先进地区和落后地区实现同步发展

A.②③④

B.①②③

C.①③④

D.①②④