. “You ___ not be too careful in the exam. Do and check your papers carefully and you ____ not take your papers out of the examination room after the exam.” the teacher told us before the exam.

Mr Black with his wife _____visiting China now.

When help，oneoftensays” Thank you,”or” It’s kind of you”[ ]

What can I do for you– I’d like to buy a present for my son, _______ at aproper price but of great use.

The expression ____ means “在20世纪50年代”.