用括号里的单词的适当形式填空。

1. How much______these pants? They are fifteen dollars. (be)

2. I'm sorry I can't remember the length of the desk. Can you tell me how______ it is? (length)

3. Can I ______ you? Yes, please. I want a T-shirt.(helpful)

4. Cindy______a new blue sweater.(have)

5. Look! The red shoes are on ______for ＄15. (sell)

（）是贸易术语所应规定的核心问题。

A.交货地点

B.风险何时由卖方转移给买方

C.由谁负责本来办理货物的运输、保险、通关过境的手续