— Peter doesn't mind lending you his camera.
— He ________. I've already borrowed one.
A:needn't
B:can't
C:mustn't
D:shouldn't
下列离子方程式表示正确的是( )
对违法犯罪的未成年人,必须坚持的方针是教育、感化、挽救。( )
下列关于高倍物镜的叙述,正确的是( )