Предмет: Математика, автор: аникол

решите пожалуйсто........

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Автор ответа: Uturna

Весь сплав составляет 100%, следовательно масса олова 100-31=69%.
Масса олова к массе сплава 69/100=0,69
Медь к олову 31/69=0,45
Олово к меди 69/31=2,23
В любых единицах измерения, т.к они не указаны в условии.

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1.We ..... a holiday last year.

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B haven’t had

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3.I .....a new dress last week, but I ..... it yet.

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A lived

B have lived

C had lived

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A have come

B came

C has come

7. ...... their telephone number.

A forgot

B have forgotten

C had forgotten

8. She ...... English for five years.

A studied

B has studied

C have studied

9. Peter ...... the money so that he could finish his education.

A has borrowed

B borrowed

C have borrowed

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A gave

B has given

C have given

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A have taken

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A sended

B have sent

C sent

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A didn’t see A saw

B haven’t saw B have saw

C haven’t seen C have seen

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B has taken

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A has made

B made

C have made

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A was

B has been

C was been

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A lost

B has lost

C losted

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A Did the post come

B Has the post come

C Has the post came

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A has felt

B felt

C feel

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A drove

B drive

C driven

D drived

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A was

B were

С have

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1.I (wake) up early and got out of bed.

A woke up

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A woke up

B had woken up

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A started

B had started

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A ever met

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B will have build up

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B will have had

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A will see

B will have seen

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A will have finished

B will finish

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A will leave

B will have left

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A will stay

B will have stayed

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A will have lent

B will lend

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A will be

B will have been