—I haven’t seen your grandfather for several years. Where has he gone?—Oh, he _____ for two years.
Water is very important for us and no one can live ______________ it.
---I'm afraid I can't walk to Quancheng Square . It's too far. --- You can ride ___________ bike.
We need to come up with an _____________ and make a decision at once.
We'll see an even stronger China in ____________ future.
—Could you tell me __________? —Sorry, I don’t know.