【题目】He wondered ________ his son was getting along with the experiment.
A.when
B.what
C.how
D.which

【答案】C
【解析】该句子为wonder引导的宾语从句，根据从句可知句意为，他在想儿子的实验进展的如何了。。How，怎么样，如何，来修饰动词短语，符合题意。故选C。