A:淀粉酶
B:脂肪酶
C:蛋白酶
D:麦芽糖酶
写作
以My Favorite Great Book为题,根据下面的问题写一篇80词左右的短文,注意适当发表自己的看法。
1 Who is the writer of the great book?
2 What is the main idea of the book?
3 Who are the important characters?
4 What is the theme of the story?
My Favorite Great Book
昼出耘田夜绩麻,村庄儿女各当家。
童孙未解供耕织,也傍桑阴学种瓜
将同一实心铁球分别投入水、煤油和水银中,静止后铁球位置如图所示.已知ρ煤油<ρ水<ρ铁<ρ水银,则铁球受到的浮力最大的是( )