Many lifestyle patterns do such _____ great harm to health that they actually speed up ____ weakening of the human body.

A．a; 不填

B．不填; the

C．a; the

D．不填；不填

在无压圆管均匀流中，其他条件保持不变，正确的结论是( )。

A．流量随设计充满度增大而增大
B．流速随设计充满度增大而增大
C．流量随水力坡度增大而增大
D．三种说法都对