题目

下图中①示肱二头肌，②示肱三头肌。完成屈肘动作需（ ） A . ①收缩、②舒张 B . ①舒张、②收缩 C . ①和②都舒张 D . ①和②都收缩 答案：A11、_____from heavy pollution for a long time, the villagers decided to clear the river. A. Having suffered            B. Suffering           C. To suffer          D. Suffered