But for friction (摩擦力), people ______ neither walk, nor even stand up.
A. can B. were able to C. will be able to D. could
It was after he got what he had desired_____ he realized it was not so important.
A. that B. when C. as D. since
He was allowed to go swimming _______ he kept near the other boys.
A. on condition that B. as far as C. even if D. as though
Since he often travels on business, he can ______ himself to sleeping in any place he can find.
A. devote B. accustom C. force D. reduce
_____ took me almost 20 years to have the courage to ask my father this personal question.
A. This B. It C. That D. One
The children _____ more to her than anything else in the world.
A. possess B. consume C. matter D. advocate
