I can hardly hear what it is saying on the radio. Would you please ________?

I think zoos provide clean and safe places endangered animals to live in.[ ]

What was the party like? —– Wonderful . It is years ______I enjoyed myself so much.

Listen! Helen is singing in the classroom.—It _______ be Helen. She has gone to Shanghai.

I’ll see to your cat when you aren’t in ? What does the underlined phrase mean ?