----Have you found the mobile phone you lost last week?----No but I’ve just bought a new

问题补充：

----Have you found the mobile phone you lost last week?

----No, but I’ve just bought a new one.

A. what

B. whose

C. whom

D. which

答案：

A. what

B. whose

C. whom

(答案→)D. which

解析：考查定语从句。本定语从句的先行词是the mobile phone，which指代先行词在句中做lost的宾语。A项不是定语从句的关系词；C在句中做定语；whom的先行词是人。故D正确。