Question

—I have worked hard at math, but it seems that I haven’t made any progress.
—Keep on _____ at it, and you will be successful.
A. work B. working  C. to work 

Answer 1

B

考查非谓语动词。句意：我在数学上很努力，但是好像我没有取得任何进步。——坚持继续努力，你会成功的。动名词做宾语表示抽象的反复性动作，固定结构keep on doing sth表示继续做某事，on是介词后面接名词或者动名词做宾语，结合语境可知选B。