地尔硫卓较维拉帕米特有的心脏作用是
A.可防治心绞痛
B.有非竞争性拮抗心肌β受体的作用
C.减慢房室结自律性
D.适用于治疗阵发性室上性心动过速
E.抑制窦房结自律性
参考答案:B
Find ways to praise your children often, ________ you'll find they will open their hearts to you.[ ]
A. till
B. or
C. and
D. but
计算题:
某台2t/h锅炉在测定时,15min内软水水表由123456.7m3变为123457.1m3,试求此时锅炉负荷。