There are a lot of signs men are more likely to have heart attacks than women.A. indicateB

问题补充：

There are a lot of signs men are more likely to have heart attacks than women.

A. indicate

B. to indicate

C. indicated

D. indicating

答案：

A. indicate

B. to indicate

C. indicated

(答案→)D. indicating

解析：There be 句型中indicate 做signs的后置定语，“有迹象表明…”indicate与signs构成主位关系，所以用现在分词形式。