One Good Reason to Let Smallpox Live It's now a fair bet that we will never see the total extinction(灭绝) of the smallpox(天花) virus. When smallpox was completely got rid of in the world, scientists wanted to 【51】______ the killer virus in the last two labs—one in the US and one in Russia. They asked: If smallpox has truly gone from the planet, 【52】______ point was there in keeping these reserves? In reality, of course, it was naive to 【53】______ that everyone would let go of such a powerful potential weapon. Undoubtedly several nations still have 【54】______ vials (小药瓶). And the last 'official' stocks of live virus bred mistrust of the US and Russia, 【55】______ no obvious gain. Now American researchers have 【56】______ an animal model of the human disease, opening the 【57】______ for tests on new treatments and vaccines (疫苗). So once again there's a good reason to 【58】______ the virus—just in 【59】______ the disease puts in a reappearance. How do we 【60】______ with the mistrust of the US and Russia? 【61】______. Keep the virus 【62】______ international support in a well-guarded UN laboratory that's open to all countries. The US will object, of course, just as it 【63】______ a multilateral (多边的) approach to just about everything. But it doesn't mean the idea is 【64】______. If the virus is useful, then let's 【65】______ it the servant of all humanity, not just a part of it.