When H7N9 bird flu first appeared,people didn’t know _____ doctors could cure it.
I feel terrible because there are ____ rules in my family.
It’s 7:30 now. Can you ____ school on time?
The number of teachers in our school ____ less than 300.
It’s always busy, so come ___ earlier to get a table.
---- the game is too hard for me. I will certainly lose.---- ___. You never say no before you try.