下列化学用语正确的是( )
A:水银—Ag
B:两个氢原子:2H
C:镁离子:Mg+2
D:纯碱- NaOH
一质点做简谐运动的图象如图所示,下列说法正确的是( )
–What did you do last Sunday?–I ________ to see the movie Tai Jiong with my friend. It was really funny.
台湾省约80%的人口祖籍为( )