--There goes the bell.--It's time for the class. Let's stop____.
A. talk
B. to talk
C. talking
D. not to talk
大量肠液丢失容易导致何种酸碱平衡紊乱
A. 代谢性酸中毒
B. 代谢性碱中毒
C. 呼吸性酸中毒
D. 呼吸性碱中毒
---I didn't come to school because my mother was ill yesterday.---I am sorry _____that.
A. hearing
B. hear
C. hears
D. to hear
下列哪项不是小肠的运动方式
A. 受容性舒张
B. 紧张性收缩
C. 蠕动
D. 移行性复合运动