We have to think very carefully before we take any action, because it's a very serious situation we have encountered.

单项选择题It took me a whole hour to solve the problem.

单项选择题Tom is still full of beans at 70.

单项选择题I didn't help him. I would have,however,I didn't have the money.

单项选择题The economic reform in Japan has been accelerated.

单项选择题It's impolite to cut in when two persons are holding a conversation.