`16` He suggested that sheets should be kept with single printed pages for drafting.

`-` Câu gián tiếp khuyên nhủ : S + suggest (chia) + S + (should) + V-inf

`-` Bị động với "should" :

`(+)` S + should + be + PII ( by O ).

`17` If we put garbage into the bins, we will minimize pollution.

`-` Điều kiện loại 1 : Diễn tả sự việc có thể xảy ra ở hiện tại (tương lai) 

`@` If + S + V (s,es) , S + will/can/may + V-inf

`18` Environmentalists suggested public should be used widely to reduce pollution. 

`-` Câu gián tiếp khuyên nhủ : S + suggest (chia) + S + (should) + V-inf

`-` Bị động với "should" :

`(+)` S + should + be + PII ( by O ).

`19` Because of the bad weather, they cancelled many flights. 

`-` Mệnh đề chỉ nguyên nhân, lí do : 

`@` Because of + N/V-ing: bởi vì

$16$ . $He$ suggested that sheets should be kept with single printed pages for drafting' .

  < $S$ + suggested/told/required/.... + $O$ + to-infinitive>

 $17$ . $If$ you put garbage into the bins , you can minimize pollution.

  <$IF$ + S +V , S + will/can/shall + V(inf)>

 $18$. $She$ dances ballet excellently .

 $19$. $Environmentalists$ suggested public transportation as a widely used method to reduce pollution.

  < $S$ + suggested/told/required/.... + $O$ + to-infinitive>

 $20$ . $Because$ of the bad weather, they cancelled many flights .

  < $Beacause$ of + N/pro/V-ing , S + V >