Construction workers attach ropes and pulleys to wooden timbers on an old bridge. They use the rope and pulley system like the one in the diagram below to move the
timbers away from each other, in order to dismantle the bridge.

It is a safe and efficient method.

Explanation:

This method of dismantle the bridge is also a good one but there are some other methods also that are used instead of rope and pulley system such as destroy the bridge by using bombs at the base of pillars and cutting of each part in order to dismantle the bridge. This rope and pulley system is also an efficient way to dismantle the bridge so that's why the engineers used this method instead of other methods due to its safe method.

a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.

the titanic would be the correct answer