1.I make my cup of coffee in the morning by pouring boiling water over ground-up coffee beans held in a special piece of paper and by collecting the brown liquid that comes through. Which techniques of the five described in the background section is/are used in the preparation of the cup of coffee

Filtration

Explanation:

Filtration is a physical separation technique that is used to separate solids from liquids or gases. The process involves the use of a filter which allows just the liquid to pass through.

In this case, the coffee beans is the solid and the boiling water is the liquid. The special piece of paper is the medium (filter) through which the coffee is collected.

The coffee coming through the special piece of paper (filter) is called a filtrate.

Filtration is used in the preparation of the cup of coffee.

frequency, z, and the collision density, z, in carbon dioxide (co2), r 180 pm at 30 °c and 120 kpa