–_____ did you work out the problem in such a short time? --With Mr. Li’s help.
—How many practical plans has your deskmate made this week? —. All have turned out disappointing.
The best times to visit Shangri-la are spring and autumn ____ the temperature is at its mildest.
Scientists study ____ human brains work to make computers.
______ in the school campus in spring, we will always noitce a colorful display of flowers.
It’s great that all the visitors who _______ on the island were saved.