A:t1℃时,甲、乙两种物质的溶解度都是50g
B:t2℃时,在两种饱和溶液中,溶质的质量甲一定大于乙
C:t2℃时,将甲的饱和溶液降温至t1℃,其溶质的质量分数减小
D:t1℃时,将30g甲放到50g水中,所得溶液的溶质质量分数为37.5%
阅读短文,判断对错。
I have a friend. It has a big screen. It can't say a word, but it can help me with my study. I use(使用) it to learn English, play a game, surf on the Internet(网络) and make friends. It's very useful(有用的). Take a good care of it, or(否则) it will be broken. Can you guess what my friend is?
如图所示的光现象中,与小孔成像的原理相同的是( )
以下对动物特征的描述,不正确的是( )