while walking along the river,they suddenly heard somebody _____for help
问题描述：
while walking along the river,they suddenly heard somebody _____for help
A called B to call C calling D calls
答
Chear sb. doing sth.” 的意思是“听见某个动作的 一部分”,或者意为“听见这个动作正在进行”； 而“hear sb. do sth.”则表示“听到整个动作”, 或者意为“听到这个动作完成了”.例如： When I passed her room, ...