单项选择题

It can be inferred that dinosaurs' low-oxygen adaptation _________.

A．was unique in evolution
B．evolved out of the low-oxygen environment hundreds of million years ago
C．is hard to explain
D．caused their extinction
<上一题 目录 下一题>
热门 试题

单项选择题
The phrase brought on (Line 1, Para 4. ) most probably means _________.
A．cause to happen
B．accelerate
C．diminish
D．sustain
单项选择题
According to Peter Ward's research, _________.
A．90% of animals and plants went extinct 250 million years ago
B．dinosaurs died off as a result of meteor impacts
C．the "Great Dying" has much to do with volcanic activity
D．global warming played a minor part in the "Great Dying"
相关试题