For and since andrew is a very hard-working student. it's midnight and he is still working at his computer. write sentences with the present perfect and for or since. ► be / at his computer / six hours he's been at his computer for six hours. 1 not / have / any fun / a long time 2 have / a cold / a week ……………………………………….. 3 not / see / his friends / ages ……………………………………… 4 not / do / any sport / last year ……………………………………… 5 be / busy with his studies / months …………