giúp mình câu 3 và 4 a. cảm ơn mn

hello teacher, my nam i.... (giới thiệu bản thân) 

here, i will talk about my topic: talk about green activities and their benefits to the environment. The first is to plant trees. Trees help absorb Co2 and release gas 02, helping to cool the atmosphere. In addition, it provides shade, fruit and can store a large amount of watter. second, is waste recycling. It helps to treat wastes that pollute the environment, some plastics can even be processed for use. the third, choose green transport like carpooling, bus or bicycle. talking the bus helps reduce a part of emissions into the air, contributing to reducing the greenhouse effect. Cycling can both avoid tracffic jams in the city, improve your health,etc.... Thank you very much. 

B

C

D

B

c

D

D

c