— You must get excited about going to France to study oil painting.

— ________, but I'm afraid I can't do well because my French is too poor.[      ]

A. I don't know yet  

B. Certainly not

C. Well, I ought to have  

D. All right

测定油品20℃的运动粘度时，粘度计在恒温浴中的恒温时间是（）min。

A.15；

B.20；

C.25；

D.10。