There _____a number of books in our school library. The number of books_______getting larger than last year.
We know that about seventy percent _____ the earth _____ covered by water.
The question is _________ .
-- Must I return the book this week? -- No, you ______. You can _____ it for 20 days.
– You shouldn’t stay up late tonight. –Thanks, I will go to bed earlier. .
The president of the USAaround the Palace Museum last month.