________ have an internal clock that controls the beating of our heart, and the ________ of our breathing.

A．Human being; steps

B．Humans; pace

C．Human beings; steps

D．Man; pace

针对国内外复杂形势，特别是我国发展中不平衡、不协调、不可持续的突出问题，提出了（）的总方针。

A.稳中求进

B.四个全面

C.坚持发展

D.五大发展