He was killing time by reading a book while waiting.

I jog for half an hour every day.

As the time limit approached, I began to panic.

I am planning to go to Inner Mongolia, an autonomous region of China, next week.

I have been to Outer Mongolia.

I have been to Chicago.

The Paleogene period was a very important time in the history of the Earth.

Let's get to work immediately.

We were given a tour of the factory by the person in charge.

He thoroughly researched the history of that nation.