题目

如图，在等腰梯形ABCD中，AD∥BC，对角线AC．BD相交于点O，下列结论不一定正确的是（ ） A . AC=BD B . OB=OC C . ∠BCD=∠BDC D . ∠ABD=∠ACD 答案：CEvery day the boy, together with his classmates, ______ to go to the playground and _____ football, ____ themselves. A. are noticed; play; enjoying             B. is noticed; plays; enjoying C. are noticed; plays; enjoys              D. is noticed; play; enjoying