3. The room is locked. She can be in.

2. –Must I finish my homework now?

　 -No, you must not.

1. When he was three, he can swim.

7. Spain began the ____ of the New World.

6. They ____ the desert in 1923.

5. They want to have a full ____ of all the possibilities.

4. He is an Arctic ____.

3. It is one day’s ____ to get to the seaside.

II. explore / exploration / explorer

2. They took a ____ to Japan last year.

I. journey / trip / travel

1. They ____ in Australia at that time.