— Can you teach me ping-pong? — Sure.[ ]
A. play
B. to play
C. plays
D. playing
答案:B
同学甲的行为:无心学习,经常旷课,甚至想辍学。
________________________________________________________________________________
微分方程cosydx+(1+e-x)sinydy=0满足初始条件的特解是()。
A.A
B.B
C.C
D.D