如图，直角梯形纸片ABCD中，AD∥BC，∠A＝90°，∠C＝30°.折叠纸片使BC经过点D，点C落在点E处，BF是折痕，且BF＝CF＝8.

(1)求∠BDF的度数；
(2)求AB的长．

单项式-2πx³y²z的系数和次数分别是（　　）

判断下列句子是否与短文相符，相符写正确，不相符写错误。

A

    Hello, I'm John. I have a room. It's big. I have a computer. I put it on my desk. I like playing football. There's a football under my desk. There is a big toy box beside my bed. In the toy box, there are three toy bears. I have a toy rabbit too. It's on my bed. I like soft toys. I like robots too. There are two robots on the shelf(书架). This is my room. I like my room.