现已明确了若干导致虐待儿童的危险因素。

A number of risk factors for child maltreatment have been identified.

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现已明确两类T细胞：辅助性T细胞(CD4)和细胞毒性T细胞(CD8)。

Both "helper" (CD4) and "cytotoxic" (CD8) T-cell classes have been described.

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现已明确该病毒源自G9群，尽管不尽相同，但与先前的H9毒株密切相关。

The results confirm that the virus is from the G9 group and closely related, though not identical, to previous H9 strains.

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