帮忙看看这几句英文有没有错,错在哪里?

帮忙看看这几句英文有没有错,错在哪里?
are your sister in class one?
the Germans is strong.
whose is that blue coat ,is it yours?
i can't see a cat,where is it.
the telephone is their.
China is largest country in Asia.
there is only a little milk in the glass.