问题
选择题
When the H1N1 virus____ at first in Mexico, no one had the least idea that it would spread so rapidly throughout the world.
A．broke off
B．broke down
C．broke out
D．broke away
答案
答案：C
考查短语辨析。句意“当H1N1病毒最初在墨西哥暴发时，没有人会想到它会传播得这么快。”A“折断，突然停止；解除”；B“分解，坏掉”；C“暴发”；D“脱离，打破”。故选C。