It has no latch , and doesn 't switch the ipad screen on and off .
它没有碰锁，不能开关ipad2的显示屏。
Through a series of experiments in ferrets , he isolated a strain with four mutations that helped the virus latch on to and infect cells in the throat .
通过一系列在雪貂身上的实验，他分离出一个具有四个突变的毒株，它们有助于病毒抓住并感染喉部细胞。
Dendritic cells normally latch on to bacteria and viruses before migrating to the lymph nodes , where they present the alien material to the immune system 's " killer " t-cells that seek and destroy such invaders .
