When a nitrogen atom sits next to a vacant spot in the carbon crystal, the intruding element provides an extra electron that moves into the hole.
当氮原子与碳晶体中的空心点相邻时，氮元素会产生特定的电子，这些电子可以移动到那个空心点里。
2
African Anopheles mosquitoes find us by our carbon-dioxide-rich exhalation. But when they get close they turn away from our heads and dive for our feet-apparently their preferred snack spot.