一、单项选择（共15小题；每小题l分，计15分）
在下列各题A、B、C、D四个选项中选择一个能填入题干空白处的最佳答案。
( )1. I woke up with______ bad headache, yet by______ evening the pain had gone.
A. the; the B. the; an C. a; an D. a; the
( )2. Sometimes smiles ______ be false, hiding other feelings like anger, fear or worry.
A. must B. can C. should D. would
( )3.---Sorry, I’m late for class again.
---Is it ______ you stayed up last night?
A. why B. how C. because D. when
( )4. Mary _____ a photo of Professor Smith while he was making a speech.
A. took B. takes C. would take D. has taken
