Since the desert air was so dry the bread quickly turned stale . in this sentence which word serves as a clue that there is cause and effect

Since the desert air was so dry, the bread quickly turned stale.

I think that the word that serves as a clue is 'Since'. You could replace since with the word 'because' and the sentence would still make sense. The word 'since' shows the readers that because of something, something else happened. It is easy to see that there is cause and effect in this sentence.

I hope this helps :)

science.

modern problems require modern solutions.