1. did done
brought brought
gave given
had had
said said
saw seen
was/were been
built built
wrote written
read read
2. l have already visited her mother
we haven't written a letter
he hasn' finished his work
people have built that new school in this year
have they learnet this poem yet?
3. two hundred and forty three
one hundred and fifty six
eight hundred and ninety seven
one thousand and six
one thousand nine hundred and eighty seven
two thousand and fourteen
fifty six
twenty four
six hudred and seventy five
eight hudred and twenty five
4. I would like to change this world for best.
The first telephone system opened in Moscow in 1882
We have been knowing each other from 1980.
People should help each other in difficult situations.