Week4.2 Solar Energy

http://environment.nationalgeographic.com/environment/global-warming/solar-power-profile/

harness: to control and use the natural force or power of something

trough: the hollow area between two waves

laud: to praise someone or something

inexhaustible: something that is inexhaustible exists in such large amounts that it can never be finished or used up

versatile: having many different uses

drawback: a disadvantage of a situation, plan, product etc

surge: to suddenly move very quickly in a particular direction

              Every hour the sun beams onto Earth more than enough energy to satisfy global energy needs for an entire year.

              There are three popular ways of changing them to electricity. First, long containers of U-shaped mirrors focus sunlight on a pipe of oil which runs through the middle. The water boiled by the hot oil generates electricity. Second, movable mirrors are used to focus the sun’s rays on a receiver. Molten salt flowing through the receiver is heated and a generator runs. Third, heat-absorbent materials heated during daytime heat a whole house.

              Now solar energy is lauded as an unlimited, non pollution, not noisy source that can be used anywhere. But it has some disadvantages. Those are not to work at night without a storage device such as a battery, to depend on weather, to be expensive, and to need many lands. In spite of these drawbacks, solar energy use has surged at about 20 percent a year over the past 15 years, thanks to rapidly falling prices and gains in efficiency. With tax incentives, solar electricity can often pay for itself in five to ten years.

Week4.1 Mosquito

http://animals.nationalgeographic.com/animals/bugs/mosquito/

vector: an insect or animal that passes disease from one person to another

evoke: to produce a strong feeling or money in someone

antipathy: formal a feeling of strong dislike towards someone or something

itchy: if part of your body is itchy, it feels slightly unpleasant, so that you want to rob it with your nails.

ubiquitous: seeming to be everywhere – sometimes used humorously

infect: to give someone a disease

eradicate: to completely get rid of something such as a disease or a social problem

saliva: the liquid that is produced naturally in your mouth

exhale: to breathe air, smoke etc out of your mouth

stab: to push a knife into someone or something

inhibit: to prevent something from growing or developing well

Mosquito

Mosquitoes sometimes are vectors which give people deadly disease such as malaria, elephantiasis, yellow fever, dengue, and encephalitis. Millions of people, especially children and the elderly, die in developing countries every year because of these diseases.

Only female have the mouth parts for sucking blood. When sucking blood, they stab two tubes into the skin: one to inject an enzyme that inhibits blood clotting; the other to suck blood into their bodies. They use blood only for their eggs. For food, both males and females eat nectar and plant sugars.

              Also, because they actually don’t choose human blood because they prefer blood of horses, cattle, and birds.

              Although we kill many mosquitoes in usual day, this has little effect, and it is said that global warming will likely increase their number and range.