He earned enough money to start his own business offering guide services tourists.
A. by; to
B. with; at
C. on; for
D. through; with
网友回答
(答案→)A. by; to
B. with; at
C. on; for
D. through; with
解析：介词by可以表示手段、原因，常置于动名词前，如：You can make the cake by mixing eggs and flour. 其次考查介词与动词offer的搭配，offer sth. to sb. = give sth. to sb.其中的to表示对象。