6.He (know)..a little english,so he wishes he ( can?speak).. it well
7. it’s 8 am. he (work)… at the office
8. you should(learn) how( keep)… the enviroment unpolluted
9. that is one of the city churches the ( destroy)..by bombing during the war
10.it is necessary (avoid)…(go)..out at rush hours
6. knows
could speak
7. is working
8. learn
to keep
9. was destroyed
10. to avoid (It is Necessary + to + [Verb in simple form] )
going (avoid + V_ing)
6.He (know)..a little english,so he wishes he ( can?speak).. it well
=> knows/ could
7. It’s 8 am. he (work)… at the office
=> is working
8. You should(learn) how( keep)… the enviroment unpolluted
=>learn/ to keep
9. That is one of the city churches the ( destroy)…by bombing during the war
=>was destroyed
10.It is necessary (avoid)…(go)…out at rush hours
=>to avoid/ going