____

在$△ABC$中，“$\overrightarrow{AB}·\overrightarrow{BC}=0$”是“$△ABC$为直角三角形”的(  )

某天文爱好者，用照相机拍摄的一张太阳照片如左图所示。这是一种____ 现象，它形成的原因是____ 。这种情况下，在树林中的水平地面上留下的光斑形状最有可能是下列哪幅图____ 。

根据句子意思，写出下列句子括号内所给单词的正确形式。
The children often get ____ (noise) in the classroom after class .
Sometimes he spends his weekend____ (fish).
Several____ (foreign)came to visit our school last week.
I think the red skirt looks as ____ (good)as the green one .
John just got his____ (driver) license.
Look!Mrs Li is there. Let's go and say hello to____ (she)?
My mother often____ (enjoy) the TV plays in the evening.
Talking loudly in a library is very____ (polite).
B.根据句子意思及所给的首字母或汉语提示，写出该句子中所缺的单词。
Li Na is a famous tennis p____ .
We can’t l____ to music when the teacher is talking in class.
The children had a____  been asleep when I got home .
Mr Li is s____ with his students and makes them work hard.
Zhou Gu was____ （采访）by the local  newspaper.
There are ____ (五十二)weeks in a year.
The doctor gave him some medicine for his serious____ (疾病)。