Ответ:

1) I have studied  French.  2)  She has eaten  octopus. 3) They have gone to Scotland. 4) We have read that book . 5) He has lived here for three years . 6) You have known David for ten years . 7) We have been  here for two weeks . 8) I have lost my keys. 9) He has drunk too much coffee . 10) They have missed the train . 11) She has gone to Peru . 12) We have eaten too much chocolate.  13) I have  had breakfast this morning . 14) John has missed the train . 15) Lucy has cooked breakfast . 16) They have wrote to the politician . 17) You have found your wallet . 18) I have met  his mother . 19) We have tried  roller-skating . 20) She has passed the exam .