HIV is a parasite that does not have enough proteins of its own to complete its life cycle.

HIV是一种寄生病毒，没有足够蛋白完成自己生命循环。

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The parasite needs two hosts to complete its life-cycle: female Anopholes mosquitoes, and the bloodstream of a vertebrate where it invades and damages red blood cells.

这种寄生虫需要两个宿主来完成它的生活史：雌性按蚊和一种脊椎动物，而疟原虫可以侵入到脊椎动物的血流中然后破坏红细胞。

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Malaria is caused by a parasite that spends part of its life cycle inside the mosquito, and is passed along to humans by mosquito bites.

疟疾的成因是寄生在蚊子上的疟疾原虫，并经由蚊子叮咬后传染给人类。

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The curious life cycle of the parasite, called plasmodium, is one of the reasons why the disease has proved so difficult to control.

BBC: Venom to arm mosquito against malaria