【C5】A．introductionB．commentC．preparationD．conclusion

HBV的s区基因编码产物是（)A．H：BsAgB．DNA多聚酶C．HBcAgD．Pre S1E．Pre S2

【C5】A．introductionB．controlC．decisionD．direction

【C2】A．callB．commentC．workD．demand

You can go to a travel agency and ask for a holiday _____.A、introductionB、bookC、brochure

You can go to a travel agency and ask for a holiday______.A．introductionB．advertisementC．b

血液中不易查到的HBV抗原是( )。 A.HBsAgB.HBcAgC.HBeAgD.pre-S1E.pre-s2