——When ___ you ____ your school trip? ——In five days' time.
A：will, have
B：have, had
C：do, have
D：did, have
解不等式组： {2x+3≤x+112x+53−1>4−x ．
已知f(x)=sin(x+π2)，g(x)=cos(x-π2)，则f(x)的图象（ ）
造成我国长江中下游地区初夏“梅雨”天气的是（ ）
