在数轴上,-4与-6之间的距离是______个单位长度.
-4与-6之间的距离是|-4-(-6)|=2.
Robin ________ volleyball quite well, but he hasn’t played it since he entered senior high school.
A.is playing
B.had played
C.used to play
D.plays
通常房屋损坏的原因主要是人为因素,包括对物业的使用不当,设计施工质量低劣、维修保养不善等等。