What is climate change? How is it caused
Define greenhouse effect.
What did the 15° United National Conference on Climate Change held in
Copenhagen on 7 to 18 December 2009 advocate? Write in short

climate change is a change in climate in the Earth 's normal weather patterns for different climates. it normally changes little by little over the years.the earth is cooler and warming .now it's getting warmer. this phenomenon is also known by as globall warming.it's causes are:

1.energy uses

2.agriculture and land use 3.Transport 4.Industries 5.Growing demands for food and water

A greenhouses is made from glass or clear plastic. It is useful for growing plants in winter in cooler climates.

sorry i don't know last one .

The 2015 United Nations Climate Change Conference, COP 21 or CMP 11 was held in Paris, France, from 30 November to 12 December 2015.

End date: 12 December 2015

Start date: 30 November                                                                       sorry i don't know last one .

Explanation:

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27