_____ is the population of China? It is about 1,300,000,000.
We won’t give up _______ we should fail 10 times.
With the guide leading the way we were able to travel ___ the forest not ___ air but __foot.
Mother asked the youngest girl _________ with her toy car.
She still remembers Beijing University ______ she graduated five years ago.
The old pianist wouldn’t listen to our request that he _______ in public again.