检查采暖立管的每个预留口的()等是否准确、平正。
A.方向
B.标高
C.半圆弯
D.角度
参考答案:A, B, C
When _____ comes to saving energy, big changes start with small steps, like turning off the lights. [ ]
A. that
B. this
C. it
D. one
祖孙相处类型的表现有哪些?