Why mercury thermometer is used to measure body temperature?

It has a low density and opaque.

Explanation:

As it is opaque, the reading of the thermometer can be read accurately

Because with changes in temperature the mercury expands and contracts and the temperature can be read from the scale.

pick it up and keep it back in

explanation:

so simple, yet people dont relize

to prevent people from getting the ebola virus, countries around the world paid to doctors develop a new vaccine. now that the vaccine has been made, doctors will need to experiment on a large number of people to find out if it works safely.

what is the greatest limitation that scientists are dealing with as they try to figure out how to experiment with the ebola vaccine?

meditation is a practice of sitting still and quiet for minutes or even hours. it has been practiced for thousands of years and is even a part of religious practices for some people. carefully controlled, repeated measurements of brain activity have shown that meditation does increase certain chemicals in the brain and even grows the part of the brain that people connect with their current surroundings and activities.

are claims about the effects of meditation most likely scientific or pseudoscientific?

not pseudoscientific, because people have made claims about it but scientific observations have not been made