--- English is _________ so difficult to me. I can’t learn it well.--- Don’t give up(放弃).

.—Wow, what ______ snow!—Yeah, it must have snowed ______ last night.

The Kings have        been to Tibet. They have decided to go there next year.

—Have you ___________ been to Beijing? —Yes. But only once.

—Do you think yesterday’s math problem was difficult? —Yes. I could ________ work it out.