—Should I look up the new words each time I come across some?—No, refer to your dictionary only ______.
___ happens, we’ll carry on the experiment.
It looks ___ it is going to rain.
___ you know the rules of swimming, you will be able to swim well.
Being League members, ___ we ought to work hard at our lessons;___ we ought to take an active part in social activities.
___ the clock structk twelve. I got home with my brother.