—Shall I give you a ride as you live so far away?  

—Thank you. _________[ ]

A. It couldn't be better.    

B. Of course, you can

C. If you like.            

D. It's up to you.

土壤样品采集后用四分法缩分，取样量一般不少于（）g，缩分后的样品应经风干干燥或冷冻干燥。

A.300

B.400

C.500