价值的______构成了农业系统中的价值流，其循环特点为______、______。
参考答案：输入和输出 非封闭式 螺旋式上升趋势
Mr. Smith has had a cast applied to his arm as an outpatient in the emergency room. Which of the following home care instructions should the nurse advice for his cast care
A．Use a ruler to reach inside and scratch under the cast.
B．Apply a heating pad to the arm for 24 hours after the injury.
C．Use powder on the skin around the cast.
D．Smell the cast for foul odors.
姜维背水破大敌（第110回）
