English Listening B1 Episode 09 - Track 10
Fill in the Blanks Exercise
Exercise (Track 10 - Molecules and Vitamin C):
Lecturer: I want to talk to you today about some very important
. A molecule is a
of different elements. Water is a molecule. It is made of two parts of
for every one part of oxygen. Water is an important molecule for the body. It is the
for most chemical reactions. In other words, it is the liquid which chemicals are
in. Dissolving is changing from
to liquid. So water is very important, but there are some other very important molecules. They are called
. You know that the body needs vitamins, but why? Because vitamins work with
, which help the human body carry out chemical reactions. For example, the enzyme
is in Vitamin C. It is very important because it makes
, which is essential for healing wounds in the skin.
Lecturer: Vitamin C may be the most
vitamin. As we have seen, Vitamin C helps to heal wounds. But it also helps the body to fight
. It may even help in fighting cancer. Vitamin C occurs in
and in fruits like oranges and lemons. On average, you should take
per day.
Lecturer: Vitamin C helps fight the disease
- that's S-C-U-R-V-Y. People have known about the disease for
. It led to many deaths in Ancient Egypt in
BCE and later, in 500 BCE in Ancient Greece and 100 BCE in Ancient Rome. But nobody knew the
. In 1536, native American Indians gave a French explorer a medicine contained in
, and his men recovered. But the knowledge did not return to Europe. In 1742, a British naval officer,
, asked for fruits like lemons to be included in the food for all long voyages. But his idea was
. Then in 1768, another British naval officer,
, gave lime juice to his sailors on a long voyage, and nobody died from scurvy. People began to realize there was a
between fresh fruit and scurvy. However, it was another
before the real cause of scurvy was established. In 1932,
, an American researcher, proved the connection between Vitamin C and scurvy.
