1980年,我国建立的四个经济特区所属的省份是( )
①广东 ②福建 ③海南 ④台湾
A:①②
B:②③④
C:③④
D:①③④
A pen is on the right of a ruler. The ruler is on the right of an eraser. That is to say, the ruler is ______ them.