— Is Sally thin or heavy?
— ________. She's of medium build.
A:Yes, she's thin
B:No, she's heavy
C:She's thin
D:She isn't thin or heavy
下列关于遗传病和传染病的叙述,正确的是( )
①浓硫酸;②浓氢氧化钠溶液;③饱和氯化钠溶液.