Complete the sentences.use for or since. the boys are tired. they have been playning an hour and a half. alex has been talking on the i came home. the telephone has been ringing about a minute. why doesn't someone answer it ? mr williams has been writing his book half a year abd hasn't finished it yet. people have been working in this the beginning of the century. john has been washington hic car nine o'clock this morning. sarah has beet waiting for her sister .. a long time
