You won’t pass the exam ________ you don’t work hard. —OK, I’ll do my best.

Would you mind me how English well

(2013·辽宁，22)He was unhappy when he sold his guitar.After all，he________it for a very long time

― It’ a fine day. Shall we go jogging ― ______ But we need to be home before six.

(2013·高考新课标全国卷Ⅱ)Since nobody gave him any help，he________have done the research on his own.