Câu 21. They / next week. / will install/ of our house /solar/ panels on /the roof 
Câu 22. next month. / will build/ a new school/ poor children /for /They
Câu 23. next month. / We /will /be using/ biogas for/ cooking and heating at / this time / 
Câu 21. hometown. /They /sell/ my/ these chemicals/ everywhere/ in
Câu 22. of this year. /They/ will /destroy the / at the end /old thermal power plant 
Câu 21. president/ Some/ on TV. /people /will interview/ the new
Câu 23. in my/ They/ hometown. /sell these/ chemicals /everywhere 
Câu 22. Friday. /They won't / sources next /show the/ film on types of /future energy 
Câu 23. Will the plumber /two days? / check/ cracks on/ pipes in/the water