已知AB，AC是半径为R的圆O中两条弦，AB=$\sqrt{3}$R，AC=$\sqrt{2}$R，则∠BAC的度数为 ____

根据句意及首字母提示完成单词
E____  in our class likes English.
I can't stand this t____ weather.
I don't like lions because they're u____  .
I don't like his new l____ .
Wang Lin is the c____ of the basketball team.
Look! There are a g____  of children on the beach.
The students are taking photos with a c____ .
Her mother is tall and a little bit h____ .
My sister is a n____  in the hospital.
We have many great s____ in the restaurant. 

下列两种物质不属于同分异构体的是             （   ）