A:3
B:32
C:12
D:23
请你根据图中的有关信息,说说风力发电开发的困难和前景.
①____
② ____
某学生取一瓶稀硫酸,等体积分装在甲、乙两烧杯中,再称取质量相等的镁带和锌粒,把镁带放入甲烧杯中,锌粒放入乙烧杯中。待反应结束后,发现甲烧杯中镁带有剩余,乙烧杯中锌粒己全部反应,根据实验现象推断,下列结论正确的是( )
— _______ is your daughter?
— She's ten months old.
— I think science is more useful than art.— I disagree. I think art is science.