什么是望远镜的有效放大率？
参考答案：
符合仪器的视角分辨率和衍射分辨率相等的视放大率为望远镜的有效放大率。
--- I didn’t see you at the party yesterday. Why?
--- Because I ________ for an important person from America at that time.
A．was waiting
B．is waiting
C．will wait
D．have waited
属于刚毛状触角的昆虫是（）
A、家蝇
B、蜜蜂
C、蝉
D、蜻蜓
