The most obvious reason why puter-based testing is being increasingly popular is that it makes tests easier .
A. take
B. taking
C. to take
D. taken
网友回答
A. take
B. taking
(答案→)C. to take
D. taken
解析：考察不定式用法。当不定式前面的形容词是对名词的性质进行说明的形容词的时候，使用不定式的主动形式来修饰名词，这样的形容词有easy, hard, difficult等。如The question is easy to answer。句意：为什么以电脑为基础的监测越来越受到欢迎的原因是他让测试更容易。故C正确。