【题目】—Where is Mother?
—She is in the kitchen. She ______ the housework all morning.
A.is doing
B.was doing
C.has done
D.has been doing

【答案】D
【解析】考查动词时态。句意：——母亲在哪里？——她在厨房里。一上午她都在做家务。现在仍在厨房做，故应用现在完成进行时，表示从过去至今一直在持续的动作。关键词是：all morning。故选D。