So difficult       it to work out the problem that I decided to ask Tom for    advice.    [      ]

A. I did find      

B. did I find    

C. I have found    

D. have I found

一般从劳动合同的期限与试用期的关系来看，劳动合同期限短的，试用期应（）

A.取消

B.延长

C.不变

D.缩短