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When do I use "sein" in the perfect tense?

In German the perfect tense is formed with haben/sein + past participle. The majority of verbs use haben in the perfect tense (such as Ich habe gespielt – I played). Transitive verbs (ve...

Answered by Nina M. • German tutor

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The area of a square is 49cm^2. The perimeter of the square is equal to the circumference of a circle. Work out the radius of the circle. Give your answer to 1 decimal place.

Area of a square (A_s) = Side length (L)²

L = square root A_s

L = square root 49

L = 7 cm

Perimeter (P) = 4L

Answered by William D. • Maths tutor

15338 Views

Explain how natural selection can lead to new species forming (speciation)

Within a gene pool of a population, there is genetic variation, due to mutation. This leads to phenotypic variation. Some individuals will be better adapted to the environment than others and will ther...

Answered by William D. • Biology tutor

35160 Views

Describe how fertiliser run-off can cause damage to a lake's ecosystem.

Fertilisers are generally high in nitrogen, to replenish the nitrogen in the soil assimilated by the crop plants. When this is drained into lakes in run-off, it can cause dramatic consequences. Nitroge...

Answered by William D. • Biology tutor

5391 Views

How can I get a high mark in an unprepared discursive essay?

All too often, A level language students fret about entering the exam room about to write an essay they haven't been able to prepare for and which they'll likely know little about. No need to worry tho...

Answered by Aleksei O. • French tutor

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