句型转换。

1. It's very hard to work out the math problem. (同义句)  

     ______ the math problem is very har.

2. I would like to come to China for my vacation. (改为一般疑问句)  

     ______ like to come to China for ______ vacation.

3. How about taking him to the Ming Tombs? (作肯定回答)  

    ______ ______!

4. Maria has to finish her homework first. (否定句)  

    Maria ______ ______ to finish her homework first.

5. We can explore the graves of ancient Chinese emperors. (就划线部分提问)  

     ______ ______ we explore?

大副的适航职责有：（）

Ⅰ保证货舱适货

Ⅱ保证救生设备处于随时可用的良好状态

Ⅲ正确装载，满足载重线及稳性要求

A.Ⅰ～Ⅲ 

B.Ⅱ、Ⅲ 

C.Ⅰ、Ⅱ 

D.Ⅰ、Ⅲ