Число общих электронных пар в молекуле метана?

When Mr Smith 1 ________(get up) in the morning the weather 2 ____ (be) very bad. It 3 _______ (be) cold outside and it 4 ____(rain) heavily. He was about to leave for his office when he 5 ____ (find) that all his umbrellas 6 _____ (be) out of order. So he 7________ (take) his umbrellas to the umbrella-maker and 8 _____ (say) that he 9 _______ (come) back and take them in the evening.
In the afternoon Mr Smith 10 _______ (go) to have lunch at a restaurant. A lady 11 _________ (come) in and 12 ________ (sit) down at his table and 13 ______ (have) lunch. Mr Smith 14 ______ (leave) earlier. By mistake Mr Smith 15 _____ (take) her umbrella and 16 ________ (go) to the door. However, the lady 17 ______(ask) him to give her umbrella back. “Oh, I 18 _______ (be) sorry,” 19 _____ (say) Mr Smith. In the evening Mr Smith 20 _____ (take) his umbrellas from the umbrella-maker and 21 _____ (get) on the train. The young lady 22 ________ (be) on the same train too. She 23 _________ (look) at his umbrellas and 24 __________ (say), “You 25 ________ (have) a good day, ______ you?”  расскрыть скобки

Приведите дроби к наименьшему общему знаменателю:                                              а)5/7 и 1/2; б)7/20 и 1/15; в)3/26 и  5/39; г)8/11 и 5/8; д)7/13 и 2/11; е)3/22 и 2/33. заранее