A:Mg(OH)2,NaCl
B:NaOH,H2SO4
C:H2,O2
D:ZnSO4,H2
—I like the photo I took on the beach yesterday. What do you think of it? —Well, really nice!
关于磁场和磁感线,下列说法中正确的是( )
设p:x<3,q:-1<x<3,则p是q成立的( )
亚洲分布范围最广的气候类型是