Вопрос школьника по предмету Алгебра
Кран с холодной водой заполняет ванну за 19 мин, а с горячей за 23 мин. Открыли кран с горячей водой. Через сколько минут нужно открыть кран с холодной водой, чтобы к тому моменьу, как ванна будет заполнена полностью, в ней холодной и горячей воды было поровну?
Ответ учителя по предмету Алгебра
23=100%
x=50%
x=23×50/100=11.5
9=100%
y=50%
y=9×50/100=4.5
11.5-4.5=7 ответ через 7 минут
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НА УРОК БИОЛОГИИ 6 КЛАСС
Состав и функции крови; группы крови; болезни крови
The Americans are very 1 (proud) of their country. They say that in the USA the buildings are 2 (tall), the cigars are 3 (long), the cars are 4 (big), and the girls are 5 (pretty) than anywhere in the world. The English don’t always agree. Some say the Americans are 6 (loud), 7 (rich) and 8 (noisy) than any other nationality. Other British people think there lots of 9 (good) things about the USA like Hollywood, jazz and superman. It is true that most American skyscrapers are 10 (tall) than buildings in the UK, but the British think their stately homes are 11 (old) and 12 (beautiful) than anything in the USA. The Americans love coke and hamburgers while people in the UK think British food is much 13(healthy). Clothes are 14 (cheap) in the USA, but fashion design in the UK is 15 (good) than design in the USA.
Ex. 4. Choose the correct verb to express a modal meaning.
7. He … speak three foreign languages.
a) can; b) may; c) must
8. You … work hard at your English if you want to know it.
a) can; b) may; c) must
9. You … not go out, the lesson is not over yet.
a) can; b) may; c) have
10. He … be in this room.
a) must; b) is; c) has
11. Must I come tomorrow? – No, you … .
a) mustn’t; b) can’t; needn’t
12. May I invite my friend to the party? – Yes, you … .
a) can; b) may; c) must
7. You feel bad, you … see a doctor.
a) needn’t; b) should; c) can
8. I … walk, there is a bus going there.
a) needn’t; b) mustn’t; c) can’t