根据情景选择合适的选项。

1.问别人需要什么？可以说：       [ ]

A. What can you see?    

B. What would you like?

C. What's your hobby?

2.你想向顾客推荐一些面包，可以说：          [ ]

A. What would you like?    

B. What about some cakes?

C. What about some bread?

3.对别人的推荐表示满意，可以说：       [ ]

A. I'd like some rice.    

B. Sounds good.

C. Thank you.

4.你询问别人是否需要帮助，可以说：       [ ]

A. Can you help me?    

B. Can I help you?

C. You can help me.

5.你想询问价钱时，可以说：         [ ]

A. How are you?    

B. How many?

C. How much?

6.你想问别人这件背心怎样时，可以说：          [ ]

A. What colour is it?    

B. What about this vest?

C. What about this shirt?

KCN是常用的隐蔽剂，可以在酸性或碱性条件下使用。