单项选择题
A.25℃ B.45℃ C.50℃ D.60℃
A.3个月 B.6个月 C.9个月 D.12个月
A.﹥10%,≧20% B.﹥10%,≦20% C.﹤10%,≧20% D.﹤10%,≦20%