室内热水供应系统中,()等均应保温,以减少热损失。
A.热水配水管
B.机械循环的回水管
C.有可能结冻的自然回水管
D.有可能结冻的水加热器、贮水器
参考答案:A, B, C, D
Do you know any singers who ____ good at writing their own songs? [ ]
A. is
B. does
C. are
D. do
红细胞分布宽度()
A.RDW
B.MPV
C.HCT
D.MCH
E.MCHC