单选题：It seemed _____ the world was at _____ end. [ ]A. as if…an..

I lived with my brother this winter and didn’t have to pay rent. So I ________ save most of my salary.A．couldB．wouldC．was able toD．should

There was an old man wandering about the corner _____waiting for someone.A. even though B. even if C. as ifD. in case

You don't want your parents to critisize you _____ you stop wearing long hair at school.A. unless B. if C. though D. so that

(2013·湖南长沙四校二模)—Is the letter from your mother?—Yes.But she ________the letter herself，because she doesn’t even know one word.A．needn’t have written　B．can’t have writtenC．might not have writtenD．should not have written

—Has Mr.Tom White arrived ?---- Yes ,already . ______he wait outside or just come in ?A．ShallB．MayC．CouldD．Must