单选题：I lived with my brother this winter and didn’t have to pay ..

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

(2010·辽宁高考)Doctors say that exercise is important for health, but it ________ be regular exercise.A．canB．willC．mustD．may

(2013·四川，5)—Why are your eyes so red？You________have slept well last night.—Yeah，I stayed up late writing a report.A．can'tB．mustn'tC．needn'tD．won't