Каждый из 7 городов соединён с другими скоростными трассами.Сколько всего скоростных трасс между этими городами?Помогите!!!!!!

помогите плиз очень надо почему кладовая солнца это БЫЛЬ И СКАЗКА?

                                                       и зарание спасибо!

Бассейн наполняется из двух труб. Из первой трубы в 1 минуту вливается 2 л, из второй - 18 л воды. Бассейн заполнится через 45минут, если открыты обе трубы. Сколько литров воды вмещает бассейн?

Помогите проверить правильно ли выполнен тест , спасибо заранее

1. Укажите глаголы в Present Perfect.

                are running

                had

                +has written

                +have asked

                +have spent

                lived

                shall go

                speaks

                went

                will ask

2. Укажите правильный перевод предложения "Я написал перевод этого текста".

                I am writing the translation of this text at the lesson.

                I have to write the translation of this text.

                +I have written the translation of this text.

                I shall write the translation of this text.

                I write the translation of this text at the lesson.

                I wrote the translation of this text at the lesson yesterday.

3. Укажите возможные краткие ответы на вопрос “Have you seen this picture?”.

                No, I don’t

                +No, I haven’t

                Yes, I am

                Yes, I did

                Yes, I do

                +Yes, I have

                Yes, I shall

4. Укажите предложения, глаголы-сказуемые которых стоят в Present Perfect.

                Have you much free time?

                +He has come to the technical school.

                +He has given me a letter.

                I have not translated the text.

                My mother is a doctor.

                She has not written the translation.

                +They have taken the pencils.

                This student has many friends.

                +We have to go to the library.

                You have to wash your hands before meals.

5. Укажите предложения, глаголы-сказуемые которых стоят в Past Perfect.

                He had a letter in his hand.

                +He had finished his work before you come.

                He had to translate the text.

                He had written a letter by 5 o’clock.

                He has a book.

                He has come.

                +They had come when you finished your translation.

                They had given us their books.

                They had six lessons.

                They have many English books.

6. Укажите предложения, глаголы-сказуемые которых стоят в Future Perfect.

                Have you written your translation?

                I had a book.

                I shall go there.

                She has come.

                +They will have finished their work by 4 o’clock.

                +We shall have translated the text when they come.

                Will you have written your translation?

                You will take my pencils.

Изотоп 137Cs имеет период полураспада 29,7 лет. 274 г этого изотопа прореагировали со взрывом с избытком воды при нагревании. Каков период полураспада цезия в образовавшемя соединении?