Section 1 

act.1 :
1- Yes.
2-No.
act.2
          South of America / 190 million  /8550000 s.km / Brasilia / Portuguese / Football
act.3 big=large/inhabitants=people/main=principal/famous=well-known

Section 2 :
act.1
1-Algeria is a large country.
2-The fennec is a famous animal in Algeria.
act.2
        participated/took/will support
act.3:
1- /s/ : inhabitants
2- /z/: has/persons/cities/covers/goes/pumas/dogs/kilometres/animals/jaguars/times
3- /iz/: foxes/

part 2
- a letter to a Brazilian friend ...Dear /Maria/Raquel /Alessandra//Roberto/Miguel/Diego/Carlos for example.
- use of the present simple
- Take inspiration from the text "Brazil" to use the right words like country/area/population/inhabitants/main cities/
- use of the superlatives like  largest/most famous/ most beautiful/oldest ,etc

Example :

Dear Miguel,
     Algeria is now the largest Arab country.It is situated in North Africa.It is bordered by Tunisia,Libya,Niger,Mali,Western Sahara, Mauritania and Morocco.  Its area is 2.381.741 s.km. It has got a population of about 38 million inhabitants .Its capital is Algiers. Oran,Annaba, and Constantine are the main cities.Arabic is the official language.
    Algeria is famous for its Roman ruins in Tipaza city. The old Casbah district in Algiers,the old city of Beni Yezgen in Ghardaia city,the palm groves in Bechar ,etc. The most famous dish here is Couscous.
  I hope one day you come and visit .I'm sure you will enjoy yourself very much.
                                                                                                                                              yours,
                                                                                                                                                        A li (not your name)