<span>A tri-fold brochure has two parallel folds, splitting the brochure into three sections. Even when printed on low-weight paper, tri-folds can stand up easily, which makes them a great choice for displaying at conventions. You can fold both folds inwards so that the left and right sections of the brochure sit on top of one another, or you can have one fold inwards and the other outwards, to create an accordion effect, which looks very attractive.</span>
Answer:4
Explanation:
Given
Frequency of beats is 3 beats per second
Frequency of first tuning fork is 
Beat frequency is difference in the frequency of tuning forks i.e.
either
or 
so 
or

so there is not enough information given to decide.
Are their any multiple choice questions? Also you said, "<span>Birds that have adapted to temperatures in their environment must find a way to adapt." It says they already adapted lol</span>