【题目】Sit down, Emma. You will only make yourself more tired, on you feet.
A.to keep
B.keeping
C.having kept
D.to have kept

【答案】B
【解析】考查非谓语动词。句意为“Emma，你坐下吧。老这么站着你会累的。”A项to keep是表示将来。C项having kept和D项to have kept表示动作先发生。make yourself more tired与keeping on you feet同时进行，故选B。