同纬度甲乙两地海拔分别是720米和1720米,甲地气温28.8℃,乙地气温为( )。
A:34.8℃
B:22.8℃
C:28.8℃
D:18.8℃
-----______ there any living things on other planets ?
-----I have no ideas. Maybe we can know more about that in the future.
如图2所示的四个情景中,人对物体做功的是( )