题目

 — Our monitor Jack is good at all the subjects, but he never .         — What a modest student!         A. gets off             B. takes off              C. puts off             D. shows off 答案：D∠A，∠B，∠C是△ABC的三个内角，下列各式成立的是A.sin=sinB.cos=cosC.tan=tanD.sin=cos