Why can't people drink salt water for a long period of time? *

Becaus drinking salt water can cause diarrhea

Explanation:

Having a healthy amount of sodium in your body is fine, but too much becomes a problem. It causes intestinal issues that lead to diarrhea, which in turn often causes dehydration due to a sudden and substantial loss of fluids.

Sea water is toxic to humans because your body is unable to get rid of the salt that comes from the sea water.  Your body normally gets rid of excess salt by having the kidneys produce urine, but it needs freshwater to dilute the salt in your body for the kidneys to work properly.

1) I am buying her a good ring.
2) I am meeting her at the airport at ten.

In the present continuous, we add -ing onto the end of the infinitive (like the words in the brackets). So “meet” becomes “meeting”. In front of the verb we put “am” or “is” or “are”, depending on the subject. Here are some examples.

We are going to the beach.
I am reading this book.
She is painting a tree.