单项选择题
A.to live B.live C.lived D.living
It was convenient（）close to work.A.to livingB.livingC.l...
单项选择题It was convenient（）close to work.
A.to living B.living C.live D.lived
The problem is（）by pollution.A.causedB.becauseC.dueD.be...
单项选择题The problem is（）by pollution.
A.caused B.because C.due D.because of
The mistake was（）by carelessness of the assistant.A.due...
单项选择题The mistake was（）by carelessness of the assistant.
A.due B.caused C.because D.owe
