问题补充：
— will you stay in Shenzhen for your summer vacation?
— For about two weeks.
A. How far
B. How often
C. How soon
D. How long
答案：
A. How far
B. How often
C. How soon
(答案→)D. How long
解析：A. How far多远，询问距离 B. How often多久一次，询问频率 C. How soon多久，一般用于将来时中 D. How long多长时间，可用于将来时或是完成时中，回答为表示一段时间的状语；句意：你暑假将在深圳呆多久呢？大约两周。For about two weeks.表示一段时间，故选D
