We shall start ＿＿＿＿Suzhou____ Ben's car tomorrow.

C

如果用by ,必须直接加交通工具.所以用in. in one's car坐某人的车

start for:

vt. 出发(动身,去动手)

例句与用法:
1. He will start for London this afternoon.
今天下午他就要动身去伦敦了。

2. If all were ready, we'd better start for the hotel.
如果一切都准备好了，我们最好动身去宾馆吧。

3. I'll start for shanghai tomorrow morning.
我明天早上动身去上海。

4. I'll start for China tomorrow.
明天我动身去中国。

5. What time do you start for work?
你几点钟去上班?

选B 肯定

我认为是选D