—Mum, I’m sorry I _____ my English test again, though I tried my best.

—Oh, believe in yourself and you’ll make progress at last.

A．passed

B．failed

C．had

D．took

世博会展区通过喷射水雾来降温．请用物态变化的知识来解释为什么喷射水雾区域的温度会降低？