结肠有哪些动脉分布？
参考答案：
结肠的动脉分布回结肠动脉、右结肠动脉、中结肠动脉、左结肠动脉和乙状结肠动脉。
Jack _____ leave _____ his teacher comes back. [ ]
A. doesn't, until
B. /, until
C. won't, /
D. won't, until
选择4G套餐并购买4G手机的客户可参加合约计划，合约计划的优惠力度最高可达（）
A、50%
B、80%
C、60%
D、30%
