When he ______ the door, he found his keys were nowhere.
If you meet difficulties when you are striving for your life goal, please ______ and you will succeed sooner or later.
Many people who had seen the film were afraid to go to the forest when they remembered the scenes ______ the villagers were eaten by the tiger.
______, ice will be changed into water.
You ______ things about. Look, what a mess in your room!
______ the train, they decided to wait for another.