对于原子吸收分光光度计，由于光栅(或棱镜)的线色散率一定，所以光谱带宽由单色器的出射狭缝宽度来决定，出射狭缝宽度在一定范围内可以调节。( )
参考答案：对
Looking after very young children _____ be very annoying sometimes, but you’ll get used to it after a while.
A．must
B．should
C．shall
D．can
简述龙卷涡旋特征（TVS）.
