【题目】—Where is Peter? I can't find him anywhere.
—He went to the library after breakfast and ________ his essay there ever since.
A.wrote
B.had written
C.has been writing
D.is writing

【答案】C
【解析】句意：——彼得在那里，我哪儿都找不到他。——他在早餐过后就去了图书馆，然后自从那以后他就一直在那里写论文。从句意中可以知道彼得是吃过早餐之后去了图书馆，从那个时候开始他就一直在写论文，这个动作一直延续到了现在，所以用现在完成时。故选C。