1型糖尿病发病的根本原因是（）
A.长期大量吃糖类食品
B.过度肥胖
C.胰岛素分泌绝对不足
D.长期用糖皮质激素
E.胰岛素相对不足
参考答案：C
Enough sleep is good for health. If you for your favorite games, you will be exhausted the next day.
A. stay up B. show up C. give up
牛的胎盘类型为（）胎盘。
