Each virus strain is grown separately inside the eggs over the course of several

游客2023-12-30 48

问题 Each virus strain is grown separately inside the eggs over the course of several days, which it is harvested, inactivated, and purified.

选项 A、from which
B、by which
C、after which
D、before which

答案 C

解析根据句意，采集、灭活和提纯发生在培养病毒之后，which指代前面整个句子的内容，因此这里用after符合句意。

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