Answer:
he body's first line of defense against pathogens uses mostly physical and chemical barriers such as sweat, skin, tears, mucus, stomach acid, and so on.
Explanation:
This is false, as the equator does not run north-south. The equators is the line that goes all around the planet in equal distance from the two poles: so it runs west-east.
It is true however that it runs roughly through the middle of the continent of Africa, but rather on the west-east axis.
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A glacial valley cross-sectional shape is a U shape whereas a stream valley is usually a V shape. The U shape comes from the scouring action of the alpine glaciers which carries rocks with it which can abrade the walls of the valley and the glacier occupies the whole valley so scours out such a shape whereas the stream cuts down and water washes in from the sides of the valley into the stream or river creating the V shape.
Answer:
In fact, you may point your flashlight (or laser pointer, if you prefer) at the Andromeda galaxy. There is a non-zero probability that one or more of the photons will be seen by some alien in that galaxy when they happen to glance into the sky at the Milky Way. However, you must take care to aim your flashlight not where Andromeda appears now, but where it will be in 3 million years. Good luck!
