In the long run, the search for sale and _____ ways of generating electricity should be continued

Question

A.economy
B.economics
C.economical
D.economic

Answer 1

【答案】：C
economy：经济，经济状况；economics：经济学；economical：经济实用的，节约的；economic：经济上的，经济学的。句意：从长远来看，对安全而又经济实用的发电方法的研究应当继续下去。