1.by half past eight they (not,have) supper yet. 2.the birds (fly) away before winter comes. 3.in five years' time we (finish) school. 4.by this time next week jack (take) his exam. 5.i hope it (stop) raining before we have to go. 6.i don't think my parents (byu) a computer by the end of the week. 7.george (not,memorize) al the idioms by friday. 8.the rogers (finish) building their new cottage before summer. 9.the party (not,start) before we get there. 10.he (not,come) back by supper time.
