I need help with this plz

Which of the following components of a pid controlled accumulates the error over time and responds to system error after the error has been accumulated? a)- proportional b)- derivative c)- integral d)- on/off.

Agas mixture consists of 8 kmol of h2 and 2 kmol of n2. determine the mass of each gas and the apparent gas constant of the mixture.

What is the correct way to measure the overall length of a boat? measure from the tip of the bow to the highest point on the gunwale. measure from the tip of the bow in a straight line to the stern of the boat. measure from the tip of the bow in a straight line to the back seat. measure from port to starboard at the boat's widest point.