"You don't have to have access to high levels of al-Qaida or the Taliban to get rudimentary tradecraft and bomb-making training."
VOA: standard.2010.05.18
If this was tetanus, you got this tetanus vaccine when you were young; you get a boost every five or ten years because your antibody levels are starting to fall.
以破伤风为例,小时候,你接种过破伤风的疫苗,每隔五年或十年要再接种一次,这是因为体内的抗体浓度会下降
There are five different levels. And then you get more money as you reach the different levels.
VOA: standard.2010.07.16
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