The Smiths _ sending e-mails letters, because it is faster. sending
A. prefer, to writing
B. prefer, to write
C. prefers, to write
D. prefers, to writing
网友回答
A. prefer, to writing
B. prefer, to write
C. prefers, to write
(答案→)D. prefers, to writing
解析： prefer A to B表示与B相比更喜欢A，主语A和B结构一定要相同。根据前文sending可知后面也要用同样结构，故选D。