某地理学习小组对我国江南某区域进行野外考察，读下图完成下列问题

小题1:学习小组绘制的由a到d四幅地形剖面图，正确的是 

小题2:当地政府计划将图2中a、b、c、d四处居民点集中到一处。从方便生活，利于后续发展角度考虑，最合适的地点是               

A．①

B．②

C．③

D．④

Many of the audience ______ asleep when they ______ the lecture.[ ]

A. fell; were hearing

B. were falling; heard

C. had fallen; heard

D. fell; had heard