—Did you have trouble ________ the house?
—No, certainly not.
A.to find B.find
C.on finding D.finding
—Did you have trouble ________ the house?
—No, certainly not.
A.to find B.find
C.on finding D.finding
D
have trouble in doing sth. 在做某事情方面有困难,介词 in 可省。