问题
选择题
Ever since he caught the N1H1, Peter _____ so much pain that he is coughing day and night.
A．suffered from
B．has suffered from
C．suffers from
D．were suffering from
答案
答案：B
题目分析：考查时态。本题根据ever since（，自从，从那时到现在）说明使用现在完成时。句意：自从他染上H1N1以后，Peter已经遭受了很多痛苦，以至于他整体咳嗽不停。故B正确。
点评：时态的考查要根据上下文的语境和语义，要抓住关键词，本题的关键词就是ever since.