The limits of a person’s intelligence, generally speaking ,are fixed at birth, but he reaches these limits will depend on his environment.
It was quite a serious accident,________caused by careless driving.
It was quite a long time________ I made it out what had happened.
—Bruce was killed in a traffic accident. —________ I talked with him yesterday morning!
Jane was disappointed that most of the guests______when she_______ at the party.
The politician has been warned that he would be getting into great trouble_______ stick to his standpoint.