—Do you think the first problem in this math test difficult?—Yes．I could        work it out．

Linda’s father hates waiting in long lines. I think he’s very _______.

They’ve got two machines, but ________ works well.

Dear students, please read every sentence carefully. ______ you are, ________ mistakes you’ll make.

 Students need at least eight hours to sleep, or they are_______ in class.