They provided silk
Hope this helped
Iraq had been severely bombed over periods of time<span />
The mountains have emerged where the tectonic plates meet. The collision of the tectonic plates can disrupt the earth causing earthquakes as well as the growth of a mountain. These mountains take awhile to become the giants they are.
I believe the correct answer would be (b)
Hydrogen is used by plants which combine it with carbon during the photosynthesis process and release oxygen into the atmosphere which is used by all living beings.