（）施基肥的范围常施于树冠投影外缘部位。
A、幼年树
B、青年树
C、壮龄树
D、衰老树
参考答案：A, B, C
—Have great changes taken place in your village —Yes. A new school was（）in the village last year.
A. held up
B. set up
C. sent up
D. brought up
通风机能力不足或过剩时应采取哪些技术措施？
