By _____, water can be changed into gas.
A.heating B.being heated C.having heated D.heated
By _____, water can be changed into gas.
A.heating B.being heated C.having heated D.heated
B
介词by后应接动名词作宾语,意为“通过…….”,表示方式。在此句中, water与heat之间是动宾关系,所以应用动名词的被动式。