1) Peter (to do) already History. 2) Kate's parents (to buy) a puppy for her this month.

1) Peter has already done History.
2) Kate's parents have bought a puppy for her this month.
3) Kate's parents bought a puppy for her last month.
4) We have already eaten your plum cake.
5) We ate your plum cake yesterday.
6) Yesterday Mary made a new dress for her doll.
7) Mary has already made a new dress for her doll.
8) Nick's father has already planted young trees in his garden.
9) Nick's father planted young trees in his garden last week.
10) The workers have already built new houses.
11) The workers built new houses last year.
12) Ann bought fresh milk for her cat yesterday.
13) Recently Ann has bought fresh milk for her cat.
14) Jack London has written many interesting novels.
15) Last year I visited the Pyramids.
16) Recently I have walked along the Great Wall in China.
17) Last week she saw beautiful tulips in Holland.
18) He has already driven through the Grand Canyon.
19) Last month I was in Norway and saw the midnight sun.
20) I have never heard such a beautiful voice.

1) Peter has already done History.

2) Kate's parents have bought a puppy for her this month.

3) Kate's parents bought a puppy for her last month.

4) We have already eaten your plum cake.

5) We ate your plum cake yesterday.

6) Yesterday, Mary made a new dress for her doll.

7) Mary has already made a new dress for her doll.

8) Nick's father has already planted young trees in his garden.

9) Nick's father planted young trees in his garden last week.

10) The workers have already built new houses.

11) The workers built new houses last year.

12) Ann bought fresh milk for her cat yesterday.

13) Recently, Ann has bought fresh milk for her cat.

14) Jack London wrote many interesting novels.

15) Last year I visited the Pyramids.

16) Recently, I have walked along the Great Wall in China.

17) Last week she saw beautiful tulips in Holland.

18) He has already driven through the Grand Canyon.

19) Last month I was in Norway and saw the midnight sun.

20) I have never heard such a beautiful voice.