The answer is; D
The plasticity of rock in the mantle and the convection currents in the region are responsible for tectonic plate movements. The hot molten rock from deep in the mantle rise and is replaced by the cooler rock at the upper mantle. These convections are similar to those of water in a boiling pot. As the tectonic plates move (as they are dragged by these convections) and collide, earthquakes are caused. In addition, at subductions zones (where two plates collide) there occurs high volcanic activity.
Answer:
Mechanical digestion begins in the mouth as the food is chewed. Chemical digestion involves breaking down the food into simpler nutrients that can be used by the cells.
Explanation:
Chemical digestion begins in the mouth when food mixes with saliva. Saliva contains an enzyme (amylase) that begins the breakdown of carbohydrates.
Answer:
to help and determine the exact age of the rocks
Explanation:
The study of rocks strata is known as stratigraphy. It is useful and helps the scientist and the researcher to study the earth's crust and its past.
Scientist could age the rock using two methods. They are :
Relative ages
Absolute ages
Early scientist could determine the exact age of the rock of the earth's crust. They use to find the relative ages of the layers of the rocks and then determine how one rock layer is older or younger than the other. But with advancement and development of carbon dating, scientist could tell the exact age of the rocks found on the earth's crust.
The Scientists uses the relative as well as the absolute dating technique to date the rock layers. They organize the rock layers based on their age and scale from the oldest to the youngest on a geologic time scale. So an exact date of the rocks can be determine by using the two methods of relative age and the absolute age.
