Choose the correct sentence: 1) Helen was unable to enter her house because she had forgotten her keys. 2) Helen

вIn the question, "Выберите верное предложение", is asking to choose the correct sentence from the given options. Let"s analyze each option to determine the correct one:

1) Helen was unable to enter her house because she had forgotten her keys.
This sentence is grammatically correct and makes sense. It implies that Helen couldn"t enter her house because of her forgetting her keys.

2) Helen was locked out of her house because she forgot her keys.
This sentence is also grammatically correct and makes sense. It implies that Helen couldn"t enter her house because she forgot her keys, causing her to be locked out.

3) Mrs Green prepared an apple pie before her grandson came to visit.
This sentence is grammatically correct and makes sense. It implies that Mrs. Green made an apple pie before her grandson arrived.

4) Sally had her lunch before she went shopping.
This sentence is grammatically correct and makes sense. It implies that Sally had her lunch before going shopping.

5) Mrs Green made an apple pie before her grandson arrived.
This sentence is similar to option 3 and is also grammatically correct.

6) My sister was mad because I took her dress without permission.
This sentence is grammatically correct and makes sense. It implies that the speaker"s sister was mad because the speaker took her dress without asking.

7) My sister was angry because I had taken her dress without asking.
This sentence is also grammatically correct and makes sense. It implies that the speaker"s sister was angry because the speaker had taken her dress without asking.

8) Sally finished her lunch before
This option seems to be incomplete as the sentence ends abruptly and does not provide any context or continuation.

Based on the analysis of the given options, the correct sentence is: 1) Helen was unable to enter her house because she had forgotten her keys.

Explanation: This sentence clearly states the reason why Helen could not enter her house, which was due to her forgetting her keys. The use of past perfect tense ("had forgotten") indicates that the action of forgetting happened before Helen tried to enter her house.