The E-mail Jack had looked forward to last night at last and he was very happy.
A. arrived
B. arriving
C. had arrived
D. arrived
网友回答
(答案→)A. arrived
B. arriving
C. had arrived
D. arrived
解析：考察句型结构，look forward to 的宾语是E-mail,主句是The E-mail arrived last night at last. 因为有last night 所以主句谓语动词用一般过去时。