—Why are you late, Jim?—Because there a lot of traffic when I came here.A. isB. areC. was

网友回答

A. is
B. are
C. was
D. were
解析：本题考查There be句型的时态。根据句意：“—Jim，你为什么迟到？—因为当我来这儿时，有许多车辆。”，原因发生在过去，而且traffic是不可数名词，本题应用is的过去式was。故选C。