Einstein’s most famous theory is ______ we call theTheory of Relativity.

With a lot of difficult problems _________, the manager felt worried all the time.

Excuse me, will the plane for Beijing within an hour—I’m not sure. You can go to the Information Desk for help.

I found my mom not feeling well this morning. I’mafraid she is ill.— _______.

How much do you usually ______ on food and clothes every month— About ￥600.