clear sky OR calm sky?

English as a Second Language English Vocabulary, Grammar and Idioms
1

Hi,

I have a piece of homework in use of English and here is the sentence which I have problem with :

If the sky is …, he sees his shadow.

A Calm B apparent C Clear D Fair

We can say “calm weather” and it is equal to not windy and nice weather, but what is the problem with clear sky ?
If you want it continues:

This means there’s going to be six more weeks of …(severe) weather and he returns to his hole.

The exercise is story named(or titled ?): “Groundhod Day”

2

The collocations are ‘clear sky’ and ‘calm weather’. What is your question?

3

Can it be “clear weather” and “calm sky” ?

4

Now I am on MC’s side here … but …

I see no reason why you cannot say calm sky …

clear sky - as it says, not a cloud in the sky …
calm sky - no thunder, lightening, fast movement of clouds and wind …etc BUT it does not mean the sky is clear or sunny!

Clear sky could give the meaning of a sunny day, but calm sky would not.