氨基酸只在等电点处有缓冲作用。()
A. 正确
B. 错误
【B2】
A. skeptical
B. practical
C. careless
D. uncertain
听力原文:How does the hair drier work?
(25)
A. Remove it.
B. Replace it.
C. Press a button.
D. Not mentioned.
听力原文:What is there under the TV?
(26)
A book.
B. A remote controller.
C. A mini-bar.
D. A pencil.