题目

The teachers often tell us _____in the river． It's dangerous．A.not swim B.don't swimC.not swimming D.not to swim 答案：【答案】D【解析】句意：老师经常告诉我们不要在河里游泳。太危险了。本题考查句型tell sb. not to do sth. 告诉某人不要做某事。语境是：老师经常告诉我们不要在河里游泳。太危险了。故选D。如图，F为正方形ABCD的对角线AC上一点，FE⊥AD于点E，M为CF的中点．（1）求证：MB=MD；（2）求证：ME=MB．