D, Mercury as a weaker gravitational pull! Due to mercury being farther from the sun and it being a smaller planet it has a weaker pull
C. Melt 1g if solid into liquid.
To solve this problem we will start from the given concept in which the number of turns is equivalent to the length of the thread per circumference of spool. That is:

Where,
l = length of the thread
= circumference of spool
For \phi we have that,

For l we have that
l = 62.8m
Finally the number of Turns would be,



Therefore the number of turns of thread on the spool are 1000turns.
I have the answer for A. Since there is blockage in the ear canal, some sound waves may not be able to get through or travel as quickly so you would have trouble hearing