It's certainly hard work. But, a man who wishes to have a career has to make a great many sacrifices.
A：on the contrary
B：in addition
C：on the other hand
D：in that case
血液是反映人体健康状态的“晴雨表”，通过对血液成分的分析，可以了解身体的许多生理状况，所以体检时常需抽血化验。
