Go straight __________ the street.[ ]
A. down
B. up
C. has
D. needs
答案:A
在如图(a)所示电路中,当闭合开关后,两个电压表指针偏转均如图(b)所示,则电阻R1和R2两端的电压分别为
A.5.6V 1.4V
B.7 V 1.4V
C.1.4V 7V
D.1.4V 5.6V
节律不整齐的脉象是()
A.动脉
B.促脉
C.缓脉
D.牢脉
E.疾脉