SB B2 progress check 5 ex 1,3,5

p 83 ex 1 question 1

p 83 ex 1 question 2

p 83 ex 1 question 3

p 83 ex 1 question 4

p 83 ex 1 question 5

p 83 ex 1 question 6

p 84 ex 3 question 1

p 84 ex 3 question 2

p 84 ex 3 question 3

p 84 ex 3 question 4