答案:B
培养根瘤菌最适宜的PH值()。
A.4.5-5.5
B.5.5-6.5
C.6.5-7.5
D.7.5-8.5
Time is money! We should()our time.
A.be fit for
B.make good use of
C.play a part of
D.take the place of