1.There were other teachers present (besides) Mr.Black.

1.There were other teachers present (besides) Mr.Black.
为什么括号里用besides,而不用escept?
2.The (surprising) look in her face suggested that she hadn't known it before.
为什么括号里用surprising,而不用surprised?
3.The man seated in the chair asked me to (be seated).
为什么括号里用be seated?
对不起,我第二题打错了,应该是选surprised,而不是surprising.