【题目】According to a new survey, every year about ______ dollars is spent to look after people with illness caused by smoking.
A.30 millions of
B.30 million of
C.30 millions
D.30 million

【答案】D
【解析】句意：根据一项新的调查，每年大约三千万美元花在因吸烟患病的人们身上。名词million前有具体的数字时，不用加s，故选D。