单项选择题
A.30℃和45℃ B.50℃和55℃ C.30℃和55℃ D.65℃和45℃
A.2/1和2/2 B.1/1、2/1和2/2 C.1/1和2/1 D.1/1和2/2
A.顺、逆和逆 B.顺、顺和逆 C.顺、顺和顺 D.逆、顺、逆