6. Ученик провел эксперимент по определению скорости поверхностной
волны. В ванночку с водой бросили
грузик с одного края. Время, за
которое волна в ванночке достигла
противоположного края 4,5 секунды.
Длины ванночки 35 см. при этом
ученик подсчитал четыре всплеска за
одну секунду.
1. Определите скорость
распространения поверхностной
волны.
2. Определите период волны
3. Определите длину
​

1. We have lived in Moscow now since 1960
2. I have studied English twice a week since childhood
3. It has been powered by the company three days a week for two years
4. They have gone to the store every Saturday since they moved here
5. We have meet each other sometimes for many years
6. I have known this man now since we went to school
7. I've been here every day since 9 o'clock
8. He has played football once a week since early childhood
9. He has driven a car now since he got the driving license
10. They have received letters from him regularly since last spring

In the main city of the north of italy everyone will find something to do to taste. how about spending the morning among the masterpieces of the renaissance, in the afternoon walking through the boutiques of the "golden square" and in the evening to put on a new outfit for the premiere in la scala? and maybe, in the morning to make a salfi on the roof of the duomo, in the afternoon to miss a glass of aperitivo and in the evening to break a voice on football? we chose the best attractions, places and activities in the capital of lombardy. read our selection and plan your perfect day in milan. take a look at the city from the roof of the duomo cathedral not 10, not 100, but for 579 years the main cathedral of milan was erected, in which a nail from the holy crucifixion is kept. one milan cathedral reminds a hedgehog, others compare it with a wedding cake, but admire the elegance of this gothic masterpiece all without exception. to the elegant appearance of the duomo, napoleon and leonardo da vinci have put their hand, and today you will see here more than 3,000 statues and impressive stained-glass windows. and if you want the spirit to capture truly, climb to the roof of the duomo: among the 135 spiers you can closer look at the 4-meter statue of the madonna and touch the figures of biblical characters, gargoyles and angels. in clear weather, the roof offers a breathtaking view of the countryside up to the snow-capped alps on the horizon.  attend to the last supper the legendary fresco "the last supper" has withstood many restorations, but the spirit of the renaissance and the ability to stir up the feelings of the audience has not lost to this day. to see the famous work of da vinci live, tickets must be bought in advance - the flow of those who wish to visit the refectory of the monastery of santa maria delle grazie does not run out from the xv century. photo: xiquinhosilva, cc by-nc 2.0 try the most delicious ice cream being in italy and not eating ice cream is almost indecent. how about a quests quest for the delicious? a lofty bar will be set by the il massimo del gelato: there are eight kinds of chocolate ice cream here - with different cocoa shares and spice fireworks. calling sweet tooth throw azteco with cinnamon and chili, giamaica with rum and fiji with grand marnier cognac and orange peel. in milan, you are waiting for the six delights of the famous grom network. its founders guido martinetti and federico grom are known for their fanatical attention to the choice of natural ingredients: in search of the perfect taste for peach sorbet, they cultivated 8 varieties of peach! every month, grom has new branded desserts: in the heat saves granite from sicilian lemons, and the christmas mood gives apple pie with apples, cinnamon and crumbs of biscotti. pistachio, coffee and salted ice cream with caramel instantly disappear from the glass at any time of the year. photo: esimpraim, cc by-nc-nd 2.0 update the wardrobe in the "golden square" for those who understand something in glamorous shopping, there are sacred places: the vittorio emanuele ii gallery, where the world's first prada boutique was opened in 1913, and the "golden square", bordered by the streets of montenapoleone, manzoni, spiga and sant andrea. if the budget allows only to stare at shop windows, the position will be saved by multibrand outlets. one of the most popular - d-magazine outlet - is right there, inside the "square of fashion", so that the things technically bought here can be considered treasures from the milan quadrilatero d'oro. photo: paul bica, cc by 2.0 do not miss: shopping abroad - the best outlets taste the famous panzerotti there is one thing in milan that can not be resisted by office clerks, students, beauties on high heels, nor sober tourists, nor even respectable elderly couples. everyone is equal to the panzerotti from luini! in these hearty italian pies, which for the milanese have long become a favorite fast food, obviously something is mixed: they want to eat instead of breakfast, lunch and dinner.