`26`.English is spoken all over the world

`\rightarrow` Câu bị động `-` Thì HTĐ : S + be + V3 / PII ( by O )

`27`.Because factories produce waste and pour it into rivers and lakes , many rivers and lakes are poisoned

`\rightarrow` Because dùng để chỉ nguyên nhân

`28`.After they had provided food , they cleaned up the debris

`\rightarrow` After + S + had + V3 / PII , S + Ved / V2

`29`.We started to learn English four years ago

`\rightarrow` S + started / began + V-ing / to V : Bắt đầu làm gì

`30`.If teachers teach environmental issues at school , students will be more aware of protecting the environment

`\rightarrow` CĐK Loại 1 :

`-` If - clause : Thì HTĐ : S + Vs / es / không s , es

`-` Main - clause : Thì TLĐ : S + will + V

`31`.What about going to the zoo ?

`\rightarrow` What about + V-ing ?

`32`.Old car tires are recycled to make shoes and sandals

`\rightarrow` Câu bị động `-` Thì HTĐ : S + be + V3 / PII ( by O )

`33`.It's very important to keep the environment clean

`\rightarrow` It is ( not ) + adj + to do sth : Như thế nào để làm gì

`34`.Breathing problems can be caused by air pollution

`\rightarrow` Câu bị động `-` ĐTKT : S + ĐTKT + be + V3 / PII ( by O )

`35`.If you study hard , you will pass the exam

`\rightarrow` CĐK Loại 1 :

`-` If - clause : Thì HTĐ : S + Vs / es / không s , es

`-` Main - clause : Thì TLĐ : S + will + V

`36`.The car is cleaned by my father every week

`\rightarrow` Câu bị động `-` Thì HTĐ : S + be + V3 / PII ( by O )

`37`.It is the first time I have spoken to a foreigner 

`\rightarrow` It is the first time + S + have / has + V3 / PII : Lần đầu tiên làm gì

`38`.Depsite being a developed country , Singapore isn't polluted by industry

`\rightarrow` Despite / In spite of + V-ing / N + Clause : Mặc dù

`\text{@ TheFox}`