问题
选择题
Engineering is ______ challenging course of study that requires ______ thoroughunderstanding of mathematics and science.
A．the; a
B．a; the
C．不填；不填
D．a; a
答案
答案：D
题目分析：考查冠词的用法区别。第一空course是课程，前面有challenging修饰，故表示泛指；第二空表示对某物的理解，understanding前加a,故D正确。