With the price of ______ petrol rising, the bicycle may become ______ popular means of transportation again. [ ]

A. the; a

B. the; the

C. /; a

D. /; the

对于员工的技能学习来说，（）是最普遍和最主要的方式。

A.高等教育

B.在职培训

C.业余培训

D.脱产培训