Jim was walking along the river he heard someone Help! Help!A. when; shoutB. while; shouti

问题补充：

Jim was walking along the river he heard someone Help! Help!

A. when; shout

B. while; shouting

C. as; to shout

D. when; shouting

答案：

A. when; shout

B. while; shouting

C. as; to shout

(答案→)D. when; shouting

解析：句意:Jim正沿着河边散步，这时他听到有人喊：“救命”。第一空when 的意思是，正在这时；while 和as 都是当…时候；hear sb. doing 听到某人正在做某事。根据句意可知选D。