70- He is cleaning his bike at the moment. 
71- We shouldn't leave our luggage here.
72- We haven't corrected this exercise yet.
73- They are going to open a shopping mall in this area.
74 I found this wallet in the hall yesterday.
75- My uncle takes his son to the park every Sunday.
76- We can't play this game today. 
77- We have to keep it secret.
78- Do people speak English in this country?
79- Someone stole my motorbike last night.
80- Don't worry. We'll help you tomorrow.
81- No one saw her at that time.
82. They often laugh at me at school. 
83- We should use cloth bags instead of plastic bags.
84- I'm going to cut those trees down.