鼻内镜手术操作一般在中鼻甲()
A.内侧进行
B.上方进行
C.下方进行
D.外侧进行
E.以上都不是
参考答案:D
The computer center, ________ last year, is very popular among the students in this school.
A.open
B.opening
C.have opened
D.opened
什么是区域外部风险评估?