Happily for john's mother, he is working harder to __________ his lost time.
A、make up for
B、keep up with
C、catch up with
D、make use of
【正确答案】:A
【题目解析】:make up for意为“弥补”;keep up with意为“跟上”;catch up with意为“赶上”;make use of意为“利用”。约翰的母亲很高兴看到他为了弥补浪费的时间而努力。