I don’t know who invented iPhone, but I think it is useful invention.
A. the; a
B. the; the
C. an; the
D. an; a
网友回答
(答案→)A. the; a
B. the; the
C. an; the
D. an; a
解析:考查冠词:句意:我不知道是谁发明了iPhone,但是我知道这是有用发明。第一空填the ,the iPhone是特指发明物,第二空填a,invention是可数名词,这里泛指一个有用的发明,选A。