When did you _____ the hospital? [ ]
A. reach
B. get to
C. arrive at
D. all the above
答案:D
健康人每日体内代谢生成的嘌呤总量为()
A.100~150mg
B.150~200mg
C.200~300mg
D.400~500mg
E.600~700mg
如图所示,若b点的电流为200mA,a点的电流为500mA,
(1)则c点的电流为多少毫安?
(2)d点的电流为多少毫安?等于多少安?