Lesson 17

a sudden, violent natural disaster that drastically alters the earth's landscape

The 2004 Indonesian earthquake and tsunami caused a massive cataclysm that claimed over 200,000 lives.

(chemistry) a substance that causes a chemical reaction to happen at a faster rate without undergoing any chemical change itself

Enzymes are naturally occurring biological catalysts that allow complex metabolic reactions to proceed efficiently in living cells.

to throw something or someone with a sudden and forceful motion

The young inventor built a small model to catapult marbles across the room.

a large waterfall where water rushes forcefully over a height

Tourists gathered to admire the majestic cataract plunging over the rocky cliff face.

the degree of roundness exhibited by a three-dimensional object

During quality inspections, defective balls that did not meet specifications for size, roundness and sphericity were rejected from production.

(geometry) a round 3D shape like a ball that is slightly flattened at the top and bottom points

The Earth is not quite a sphere but is better described as an oblate spheroid flattened at the poles.

a measuring tool used to determine the roundness of a curved surface

To pass inspection, the ball bearings needed a spherometer reading within tight tolerances for its spherical shape and diameter.

someone who moves from one country to another with the intention of settling there permanently

Ellis Island was the gateway for millions of European emigrants seeking a new life in the New World.

to leave one's own country in order to live in a foreign country

Many Irish emigrated to America in the 19th century due to poverty and famine in their homeland.

to disturb or unsettle someone, causing them to feel worried or uneasy

The constant noise from the construction site perturbed the residents, disrupting their peace and quiet.

a disruption or disturbance of a normal state of mind or emotions

The looming deadline was a constant perturbation to her otherwise calm demeanor as she worked.

to pour fat, juices, or other liquid over the surface of food, such as meat or vegetables, while it is cooking

I'm basting the turkey with butter every 15 minutes as it roasts in the oven.

a group that defends a principle

someone who spends or uses resources recklessly or wastefully

Though he had wasted his inheritance, the community still saw him as a fellow man, not as a prodigal.

impressively great in amount or degree

The earthquake caused a prodigious amount of damage to the city.

a remarkable example of a particular quality, skill, or achievement

The sequoia tree's height is truly a prodigy of natural growth in the plant kingdom.

an individual, often a leader or authority figure, who possesses the power to create laws, particularly not directly elected by the people

Moses is considered one of the most important lawgivers in history for delivering the Ten Commandments to the Israelites.

someone who can write or approve a law as a member of a legislative body, usually elected by people

After years of advocacy, the bill was finally passed when a critical mass of lawmakers recognized the urgent need for reform.