本题目来源于试卷: HL Topic A2.3 Viruses，类别为 IB生物学
[问答题]
6. The graph shows the known number of Ebola infections worldwide from 1976 to 2015.
[img]data/attachment/exam/2501/24/2501241129276426.jpg[/img]
(e) A vaccine was trialled in 2018 and shown to be effective. It was madeub e-;h cfuf.k.4utw+h .jyq4 widelyhqf.t-k .+w uf44.jy uu bec;hlcf svz3k nt1z a(o---pq.vu jt+pvo27q h+ (a available from 2020. Suggest why a vaccine against a viral infection ma cv z+- v q3f n7-puo2tjqhlp+1((z.s-kt vaoay prove ineffective in the long term.
参考答案: (Viral) mutations could make the vaccine ineffective agains the mutated virus.
Note:- Do not accept that the virus becomes resistant or host becomes resistant.
本题详细解析:
暂无
| 
