How did you find your visit to the Summer Palace yesterday—______. I got separated from my 80-year-old grandparents.

He devoted his whole life ________ animals in danger.

Is your uncle Tom a soldier— No, but he once _____ in the army for 4 years.

we think of communication, we ____think of using words, talking face to face, writing messages, and so on

This is one of the most interesting cities I have ever visited.