| 1. | Many insects use crucifers as hosts .
许多昆虫以十字花科植物为寄主。 |
| 2. | An infection thread is formed by the cytoplasm of the host cell .
侵染线是由寄主细胞的细胞质形成的。 |
| 3. | The organism must be found again in the artificially infected host .
必须在人工浸染的寄主中，再次发现这种有机体。 |
| 4. | In general an aphid cannot or hardly identify its host at a distance .
在一定距离以外，蚜虫通常不能或难以识别其寄主植物。 |
| 5. | Disease-producing bacteria develop normally within the tissues of an infected host .
致病的细菌通常在罹病的寄主的组织里发展。 |
| 6. | Degree of sensitivity or tolerance of the host can be assessed according to the symptoms .
根据症状能确定寄主感病或耐病的程度。 |
| 7. | Many of these microbes were observed in the infected host by light-microscope .
人们用光学显微镜，在受侵染的寄主中观察到这些微生物。 |
| 8. | It is capable of being integrated into the continuity of the host cell dna as provirus .
它能作为原病毒入寄主DNA细胞的连续整体中去。 |
| 9. | The outer of the two membranes around a chloroplast could be regarded as the host exclusion membranes .
围着叶绿体的外面两层膜，可以看作寄主排斥的膜。 |
