A:望远镜
B:照相机
C:显微镜
D:近视镜
用简便方法计算.
①146+451+54=
②932﹣27﹣73=
③767+299=
④482﹣203=
加入的A为____溶液,现象a为____,现象b为____.
On Sunday morning I usually ____ (get) up early.