原子吸收谱线的宽度主要决定于( )。
A．自然变宽
B．多普勒变宽和自然变宽
C．多普勒变宽和压力变宽
D．场致变宽
参考答案：C
While large numbers of residents in this area _____ the A/H1N1 flu, very few suffered death.[ ]
A. picked up
B. took up
C. brought up
D. caught up
灌水方法一边拿按照水输送到田间的方式和湿润土壤的方式，分为几种？
