Heating,ventilating,andairconditioning(HVA C)systemsare______inmostofundergroundsubwaystationstoprovidecomfortableandfreshairtoundergroundsubwaystations。
A.assembled B.installing C.equipped D.installed正确答案D
Heating,ventilating,andairconditioning(HVA C)systemsare______inmostofundergroundsubwaystationstoprovidecomfortableandfreshairtoundergroundsubwaystations。
A.assembled B.installing C.equipped D.installed正确答案D