问3道英语选择题Every girl student and every boy student in our scho

Every girl student and every boy student in our school ___ to wear their school uniform on weekdays.为什么选is required而不是are required?因为every 修饰名词,表示“每一个”,做主语时谓语动词自然要用单数.
Some of the passengers appear ___ in the accident 为什么选to have been injured而不是to be injured?强调的是结果,即“在这次事故中出现的一些人（已经）受伤上了.”
___ the city lies the famous beautiful mountain.为什么选Southeast 40 miles of 而不是Southeast 40 miles to 也不是To 40 miles southeast of?
表示“距这个城市东南40公里（因为山在这个城市之内）”

every 强调全体中的个体。
to have been injured现在完成时的被动语态，根据句意，乘客们已经收到伤害，而填to be injured 是将来的意思
Southeast 40 miles southeast of 第二个Southeast名词化说的是城市东南方向的东南处