Chalk is a soft white powdery limestone that's made with fossil shells of foraminifers. Chert is a hard dark opaque sedimentary rock which is made of silica with an amorphous fine grained texture.
<span>Although China's agricultural output is the largest in the world, only about 15% of its total land area can be cultivated. China's arable land, which represents 10% of the total arable land in the world, supports over 20% of the world's population. </span>
If the rains fail it can cause<span> drought in addition to natural factors, the land is marginal. Human activities such as overgrazing, overcultivation and the collection of firewood can lead to desertification, particularly when combined with drought conditions. hope this helps and plz rate below :)</span>
Earthquakes occur along plat boundaries and faults. Most earthquakes happen along the edge of continental and oceanic plates. Faults are found in the middle of the plates. They're like cracks that form when the different parts of the plates don't move in the same direction.
