A:5∶4
B:5∶3
C:1∶1
D:3∶5
(____) These are all books about science.
(____) That's a good idea.
(____) Let's put them on this shelf.
(____) We can put them on Shelf B.
(____) Let's make a home library.
某同学上肢的伤口感染,医生在其臀部注射药物治疗,药物到达伤口经历的血液循环路线是( )