1. A viral illness left her barely able to walk. 一场病毒引起的疾病使她走路十分困难。
2. Nuclear polyhedrosis viral infection is one factor these disparate species share. 核多角体病毒感染是这些不同物种共有的一个因素。
3. In stands dominated by trees such as aspen, however, incipient gypsy moth outbreaks are quickly suppressed by viral epidemics. 然而，在以白杨等树为主的林分，最初的舞毒蛾爆发很快就被病毒流行病所抑制。
4. In response to viral infection, the immune systems of mice typically produce antibodies that destroy the virus by binding to proteins on its surface. 在病毒感染的反应中，老鼠的免疫系统通常会产生抗体，通过与病毒表面的蛋白质结合来破坏病毒。
5. The recent work has been made possible by new techniques of molecular biology that allow viral DNA to be detected at low concentrations in the environment. 分子生物学的新技术使最近的工作成为可能，这种新技术能在环境中检测到低浓度的病毒 DNA。
