单项选择题

Not until Kentucky's Mammoth Cave had been completely explored in 1972______.

A．when was its full extent realized
B．that its full extent realized
C．was its full extent realized
D．the realimtion of its full extent
<上一题 目录 下一题>
热门 试题

单项选择题
The Chisos Mountains in Big Bend National Park in Texas were created by volcanic eruptions that occurred ______.
A．the area in which dinosaurs roamed
B．when dinosaurs roamed the area
C．did dinosaurs roam the area
D．dinosaurs roaming the area
单项选择题
You don't object ______ you by your first name, do you
A．that I call
B．for calling
C．that I am calling
D．to my calling
相关试题