Molly plays _____ her friends every day.
A. for
B. with
C. on
D. up
答案：B
背中央2～4行鳞片强烈起棱，脊部高耸成屋脊状的药材是
A．金环蛇B．蕲蛇C．乌梢蛇D．金钱白花蛇E．黑背白环蛇
简述知识、技能和能力的关系。
