Millie ran back to school because she her magazine in the classroom.A. leftB. forgotC. had

问题补充：

Millie ran back to school because she her magazine in the classroom.

A. left

B. forgot

C. had left

D. had forgotten

答案：

A. left

B. forgot

(答案→)C. had left

D. had forgotten

解析：句意：米莉跑回了学校，因为他的杂志丢在教室了。结合语境可知下文描述的是过去某时前已经完成的动作，故用过去完成时态。选C。