B) lever and pulley is the answer
Answer:
Selenium is a semiconductor
Explanation:
Selenium is a semiconductor.
Elements in the column IV and VI of the periodic table are referred to as Semiconductor.
Selenium lies in the column VI along with Tellurium
Some other elements of the column IV are silicon, germanium, and tin
Answer:
CO2 emissions from fossil fuel burning should be minimized at all cost. The CO2 are gotten when the carbons from hydrocarbons react with air(oxygen). This gas erodes the ozone layer which makes the melting of ice caps faster due to increased amount of heat radiations on the earth. This is the only best and permanent solution to the reduction of the amount of heat rays on the earth which is a global problem.
Objects which reflects back the sunrays could also be inserted into the sea to prevent the melting of the ice caps.