高校毕业生就业专业结构性矛盾的主要原因，是由于很多高校在（）方面存在问题。
A.招生人数
B.就业推荐
C.专业结构和人才培养
D.思想教育
参考答案：C
The boy has been going back home later _____, which worries his parents.[ ]
A. as usual
B. than usual
C. as usually
D. than usually
火灾风险评估根据评估对象的不同分为哪几类?
