()是微生物检测的常用仪器,借助它可以观察到肉眼看不见的微小物体。
参考答案:显微镜
We should bear in mind that social development and balance of nature should go in ________. [ ]
A. company
B. sympathy
C. association
D. harmony
图1中大中小三个圆分别代表河外星系、太阳系、地月系,能正确表示三者相互关系的是