Read the following passages and then choose the best answer for each question.
Tube worms live anchored to the sea floor, 1,700 feet below the ocean surface, near natural spring vents that spew forth water from the earth. They live off geothermal energy instead of sunlight. There are two species of the tube worm family, with very different lengths of life and growth rates, but similari-ties as well.
The slow-growing tube worms are known to live as long as 250 years, making them the longest-living sea invertebrates known. This species lives near cold sea-floor seeps and may not grow at all from one year to the next. Even when they do grow, it is generally from a half an inch to four inches per year. In spite of their slow growth, due to their long lives, they can reach nine feet before they die, although they are thinner than the hot-water worms.
The seeps under the slow-growing tube worms are rich with oily materials. The envi-ronment in which they live is slow and peaceful, stable and low-energy. The cold-water seeps and the tube worms that reside there may live hundreds or thousands of years.
In stark contrast, the fast-growing tube worms live a quick and short life, growing rapidly. They attach themselves near hot steaming vents that force water into the sea, growing about two and a half feet a year, and up to eight feet overall. They live by absorb-ing sulfur compounds metabolized by bacteria in a symbiotic relationship.
The hot water vents spew forth scalding water filled with hydrogen sulfide, which the tiny bacteria living in the worms’ tissues consume. These tube worms live a rapid life, with none of the relaxing characteristics of the cold-water tube worms.
1. The word anchored in the first sentence is closest in meaning to