The Выбери ответ n't thick. — It isn't very this morning.

Краткое пояснение:

Пошаговое решение:

1. The sentence structure is 'The [noun] n't thick. — It isn't very [adjective] this morning.'
2. From the visible options, 'clouds' is a plural noun. 'cloud' is a singular noun. 'cloudy' is an adjective.
3. If the blank is for a noun, and the sentence is 'The [noun] isn't thick...', then 'clouds' or 'cloud' could be the subject.
4. The phrase 'isn't very' suggests an adjective follows.
5. Let's consider the options again. If the first blank is 'clouds', the sentence would be 'The clouds isn't thick.' (grammatically incorrect, should be 'aren't'). If the blank is 'cloud', 'The cloud isn't thick.' is grammatically correct.
6. The second part 'It isn't very...' needs an adjective. 'cloudy' is an adjective.
7. So, if the sentence is 'The cloud isn't thick. — It isn't very cloudy this morning.', it makes sense.

Ответ: The cloud isn't thick. — It isn't very cloudy this morning.