定语从句
Theclassroomisanaturalenvironment()andapplytheconceptofcommunityservicetoreducelocalcrimesciences.
A、whichtointroduceB、tointroduceC、inwhichtointroduceD、whichtointroduce
请问此题选择必须要有介词in的原因是固定搭配inclassroom吗?感觉选B也读的通啊,不要in也行啊.