Drugs mainly affect the brain. After taking drugs for a few days, your very addicted to the substance, and want a lot more of it. If you don't get more, it kills you confidence and well being, and this leads to depression and other seriously bad thoughts.
The <em>older violins</em> are more than one object, in this case its cannot be used, only their; <em>each violinist</em> could mean male or female, so it would be possible the use of his or her or their (applied for either),but there is only the latter option. The correct answer is their/their.
<em>The older violins no longer had their original parts, but each violinist played their instrument well.</em>
