单项选择题

The price of aluminum was sharply reduced when people discovered a new refining process with the aid of ______.

A．wind
B．solar energy
C．hydraulic power
D．electricity
<上一题 目录 下一题>
热门 试题

单项选择题
Which of the following best summarizes the passage
A．A Sudden Cure.
B．Two Patients.
C．Captain and Sailors.
D．A Difficult Voyage.
相关试题