Fill in the gaps with verbs in the proper progressive form . i. listen! the birds (sing) 2. we (drive) to the mountains this time next saturday. 3. they (have) a picnic, when the rain started 4, i (read) a book last evening when i heard the fireworks. 5. s! be quiet! my little sister (sleep) 6. they (not / do) their homework this afternoon: tomorrow's the weekend. 7. by this time tomorrow l (swim) ..in the central pool. 8. mark and i (play) a computer game now. 9. i saw them. they (wait) in front of the shop.