21.（ ）

(单选题)A good education is an ______ you can fall back on for the r (单选题)The most basic reason why dialects should be preserved is th (单选题)______ has already been pointed out, grammar is not a set of (单选题)The boy slipped out of the room and headed for the swimming (单选题)Which of the following is INCORRECT? (单选题)So why not, the teacher reasoned, ______ him a few minutes t (单选题)I strongly advise ______ drinking too much coke. It’s unheal (单选题)Not far from my home there was a garden, ______ owner was a (单选题)I have been dreaming of ______ such a good opportunity for s (单选题)It was the experience ______ he had at school ______ made hi