The weather turned out to be fine yesterday. I ______ the trouble to carry my umbrella with me.

A．should have taken

B．could have taken

C．needn’t have taken

D．mustn’t have taken

锅炉蒸发量及过热蒸汽压力的调整控制，是通过增减（）和（）来保证过热蒸汽压力稳定，从而使锅炉蒸发量的变化与机组负荷变动相适应。