问题详情

The plant “sumpweed” is mentioned in line 25 in order to
A．contrast a plant with high nutritional value with one with little nutritional value
B．explain the medicinal use of a plant
C．clarify which plants grew better in places where trees were not cut down
D．provide an example of a plant that was easy to domesticate请帮忙给出正确答案和分析，谢谢！