我会照样子写词语。

1．例：仔细  仔仔细细    

     高兴__________    明白__________  许多___________

2．例：又唱又跳

     ____________     _____________   _____________

Lawrence Craven, a doctor from the USA, is the author of several published reports, one of ________ 

 introduced the idea in 1953 ________ aspirin could reduce the risk of heart attacks.[ ]

A. them; when        

B. which; that

C. what; that          

D. which; when