---When shall we leave for Shanghai?---We won’t 　　　 we have visited all the places of inte

问题补充：

---When shall we leave for Shanghai?

---We won’t we have visited all the places of interest in Nanjing.

A. until

B. while

C. as

D. since

答案：

(答案→)A. until

B. while

C. as

D. since

解析：until 直到……才；while 然而，当……时； as由于，随着； since自从……以来；句意：我们什么时候动身去上海？——我们直到参观了南京所有有趣的地方才去。