We had to stay at home ______ it was raining hard.

The number of people visiting the exhibition ______ 50, and a number of them ____ painters.

Have you been to the theme park—Of course. I ________ it several times when I was in university.

I know of him, but I have no idea ______. [ ]

As the library rule goes, you should put the dictionary_________ you can find it easily.