—Not only the young but also the old are getting interested _____ WeChat (微信).—They can communicate more freely.

We want to know       he will come back, as we are worried about his safety.

 I ______ an hour finishing my homework yesterday.

----Who will come and_______ if you don’t?----Either my father or my brother will come to the airport.

It began to rain ______ I was walking in the park.