A:43
B:53
C:233
D:3
直接注射抗体或注射疫苗都可以使人体获得免疫.如图是某人获得抗破伤风芽孢杆菌抗体的两种途径及其抗体的变化情况.下列有关说法不正确的是( )
⑴What are you doing?____ A. She will get a present.
⑵What happened to him?____ B. He was lost.
⑶What will Jenny get?____ C. She must hurry up
⑷What must she do?____ D. I'm reading a story book.
⊙O的直径AB=10cm,弦CD⊥AB,垂足为P.若OP:OB=3:5,则CD的长为( )