19．________(n.)苦难；痛苦 20．________(n.)砖；砖块 21．________(n.)水坝；堤堰 22．________(n.)轨道；足迹；痕迹 23．________(n.& vt.)援救；营救 24．________(n.)电；电流；电学 25．________(n.)灾难；灾祸 26．________(n.)矿；矿山；矿井 27．________(n.)矿工 28．________(n.)掩蔽；掩蔽处；避身处

suffering

brick

dam

track

rescue

electricity

disaster

mine

miner

shelter