Read these sentences and fill in the gaps with 'could', 'can', 'couldn't', 'can't'.
1. Jack says he (?) speak four languages.
2. I (?) finally talk to John after I tried to reach him on the phone for hours.
3.I (?) run very fast when I was fifteen years old. 

The obvious, but I cannot but mention: if the Belarusian nature is being destroyed, it is not frightening pace, and in itself actually remains untouched. I with his attraction to natural beauty only glad. We do not have mountains and sea, but there are endless forests, rivers and lakes. Without scorched steppes and bald hills, without salt marshes and rocky soils, but with an abundance of greenery.

A huge number of people live in much worse conditions in terms of the environment. Our eyes are blurred, everything seems ordinary and boring to us, but the value of the Belarusian nature does not diminish

1) Bob was not writing a letter at 5 p.m
2)It was not snowing when they returned home 3)The wind was not blowing from the east 4)It was not raining the whole day yesterday 5)The boys were not talking when I saw them
6)Nick was not writing for Mary when we saw them 7)Mary was not singing when he came home 8)It was not snowing hard when father returned home from the office 9)The car was not moving quickly when something wrong happened 10)I was not watching Pirates of the Caribbean at noon yesterday