单项选择题

The best title for this passage is ______.

A．Water Conservation
B．The Hydrologic Cycle
C．Underground Water
D．Polluted Groundwater
<上一题 目录 下一题>
热门 试题

单项选择题
Clouds are formed from ______.
A．water vapor
B．evaporation
C．the hydrologic cycle
D．groundwater
单项选择题
According to the author, the importance of greenspaces in the urban environment ______.
A．is still unknown
B．is being closely studied
C．is usually neglected
D．has been fully recognized
相关试题