The Egyptians were the first people to use a paste to clean their teeth around 5000 BC. But the first modern toothpaste was invented in 1824 by the dentist, Peabody. The first commercially produced toothpaste was sold in a jar in 1873.

Toothpastes mainly contain water, abrasives, including aluminum hydroxide, calcium hydrogen phosphates, calcium carbonate, silica, hydroxyapatite and fluoride.

(a)  sour and sharp to the taste
 (                    )

(b)  substances that react with acids to form salt  (                           )

(c)   orange, lemon, and grapefruit   (                        )

(d)  connected with buying and selling, and making a profit               (                       )

(e)   substances used for polishing or cleaning a hard surface.  (           )

______________________________________________________________________

(b)  Using the simple past
______________________________________________________________________

Read this article about the neurons, the basic functional units of the nervous system that generate electrical signals. The signals transmit information over long distances. 

There are 3 basic functions of neurons:

The fight or flight response is an automatic physiological reaction to a physical danger, such as encountering a growling dog. The perception of threat activates the nervous system and prepares the body to fight or flee. This results in an increase in heart rate, blood pressure, and breathing rate. After the threat is gone, it takes between 20 to 60 minutes for the body to return to its pre-arousal levels.

Some people still feel the threat due to what is called phobia. A person who is terrified of heights might experience stress response if they have to go to the top floor of a skyscraper to attend a meeting. Their body might go on high alert, with their heartbeat and respiration rate increasing.

The information is taken from these resources:

(b)  Explain what happens when you see a fire by referring to the 3 functions of neurons. ___________________________________________________________________________

     (c) What did you expect the article to be about when you read the title?

         ____________________________________________________________________________

 

Communication is one of the 21^st century skills. It helps you to convey your ideas and thoughts effectively.

Powerful speakers such as celebrities can send effective messages to people about global problems, such as saving the environment from pollution. Many celebrities have started campaigns to save the globe from pollution.

Leonardo DiCaprio, a famous actor, was involved in a series of environmental causes, forest preservation, clean water access and renewable energy. He established a foundation and donated over $30 million toward restoring balance to threatened ecosystems communities. DiCaprio produced a documentary film on global warming, entitled the 11^th Hour.

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2.  I will write a story of a famous figure who is interested in the environment and pollution.

    Make sure to:

    -Write between 100-120 words

    -Use the correct tense

    -Introduce your famous figure’s name, occupation, place of living, his/her cause
 -Justify your choice. (Why did you choose him/her)