国家机关、行政执法部门工作人员每年通过各种形式学习法律知识的时间应不少于多少学时？（）

A.三十

B.四十

C.五十

D.六十

Speaker A: It took me ten years to build up my business, and it almost killed me.

Speaker B: Well, you know what they say:().

A. There is no smoke without fire.

B. Practice makes perfect.

C. All roads lead to Rome.

D. No pains, no gains.