The Town Hall _____ in the 1800's was th
题型：选择题
问题：
The Town Hall _____ in the 1800's was the most distinguished building at that time. [ ]
A. to be completed
B. having been completed
C. completed
D. being completed
题型：选择题
| 夜间，居民楼的楼道里只是偶尔有人经过，“长明灯”会造成浪费．科研人员利用“光敏”材料制成“光控开关”--天黑时自动闭合，天亮时自动断开；利用“声敏”材料制成“声控开关”--当有人走动发出声音时自动闭合，无人走动时自动断开．若将这两种开关配合使用，就可以使楼道里的灯变的“聪明”．这种“聪明”的电路是图中的（ ） A．
B．
C．
D．
|
