Smith said he would pay ____second visit to Hangzhou ____ next month.
It is the first time that the local education authority ________ such strict requirements on going-to-school time for primary and middle school students.
There are over 58, 000 rocky objects in ________ space, about 900 of which could fall down onto________ earth.
Although the novel isn’t popular among adults, it ______ the youth, especially boys.
The experts were doing their experiment in the lab, ______ what happened outside.
In my opinion, a true friend is the one who always ______ when you are depressed.