单项选择题

Only recently（）to realize the dangers caffeine might bring to our health.

A．that scientists began
B．have scientists begun
C．scientists have begun
D．that did scientists begin

<上一题 目录 下一题>
热门 试题

单项选择题
The U. S will never again have as a nation the spirit of adventure as it（）before the West was settled.

A．could
B．was
C．would
D．did
单项选择题
（）to be the symbol of the city, the sculpture has been well preserved.

A．Considering
B．Being considered
C．To consider
D．Considered
相关试题