单项选择题
A.18℃-28℃,40%-65% B.21℃-25℃,40%-65% C.18℃-28℃,30%-75% D.21℃-25℃,30%-75%
A.尼龙 B.木头 C.硬橡胶 D.特氟龙
A.摩擦 B.感应 C.电容改变 D.湿度变化