如图,在⊙O中,∠ABC=50°,则∠AOC等于
(+32)×(-60.6)×0×(-9)=______
-0.4×0.2=_______;
(-5)×(3)=_______;
(-3)×(-0.3)=_______;
确定下列各个积的符号,填在空格内:(1)(-7.4)×(-3.2)_______;(2)(-2)×(-2)×2×(-2)________;(3)(-)×(-)×(-)×(-)