The Great Green Wall will stop the windfrom ____ the earth away.

The task is very difficult. I wonder whether we will be able to finish it in the ________ of any other helpers.

When asked to explain ____ made her remain so young , she began to tell us her secret.

Nothing is so easy as ________ parents toraise their expectations of their children too high.

_____ does Lucy learn Chinese— She learns it _____ reading novels(小说).