如图所示,赛艇的桨可看成一个杠杆.则赛艇的桨属于______杠杆.
运动员在使用船桨的过程中,动力臂小于阻力臂,属于费力杠杆,费力但省距离;
故答案为:费力.
According to the schedule, the Project was originally planned to finish in February next year.
治疗洋地黄中毒所致的室性心动过速,宜首选()
A.钾盐
B.利多卡因
C.普罗帕酮
D.胺碘酮
E.普鲁卡因酰胺