-Shall we go for a picnic tomorrow?
-Well, it all ____________ the weather.
A:belongs to
B:happens to
C:depends on
D:concentrates on
His sister always comes here ________ eight ________ the morning.
(Ⅰ)令 t=12sin(π32x) ,x∈0,24,求t的取值范围;
(Ⅱ)求函数M(a);
(Ⅲ)为加强对环境污染的整治,市政府规定每天的综合环境污染指数不得超过2,试问目前市中心的综合污染指数是多少?是否超标?