Great changes ______ in China in the past 20 years.
31.— I'm wondering why the visitors chose to stay with the host family. — _____real local life.
30.How long do you think it will be _____ we can find a new water source?
29.High up in the mountains _____ a quiet small village, with only 20 households.
28.A heavy snow promises a good harvest, _____ is often the case.
27.After his wife died, he kept himself _____ from other people and the outside world,