Vocabulary Development 1

Task 11. Choose the most suitable words (not all!) to fill in the gaps.

PART A

plane circular giant terrestrial consists orbits outer metal gas massive ice planets

The Solar System 1_________ of the Sun and its planetary system of eight 2________, their moons, and other non-stellar objects. It formed 4.6 billion years ago from the collapse of a 3_________ molecular cloud. The vast majority of the system's mass is in the Sun, with most of the remaining mass contained in Jupiter. All planets have almost 4__________ 5_________ that lie within a nearly flat disc called the ecliptic 6__________.

PART B

plane circular giant terrestrial consists orbits outer metal gas massive ice planets

The four smaller inner planets, Mercury, Venus, Earth and Mars, also called the 1__________ planets, are primarily composed of rock and 2__________ . The four 3__________ planets, called the 4_______ giants, are substantially more 5___________ than the terrestrials. The two largest, Jupiter and Saturn, are composed mainly of hydrogen and helium; the two outermost planets, Uranus and Neptune, are composed largely of ices, such as water, ammonia and methane, and are often referred to separately as "6________ giants".

Task 12. Use all the words to fill in the gaps. Do not change the form of the words.

PART A

further interstellar approximately bubble flow scattered

The solar wind, a 1_________ of plasma from the Sun, creates a 2________ in the 3________ medium known as the heliosphere, which extends out to the edge of the 4________ disc. The Oort cloud, which is believed to be the source for long-period comets, may also exist at a distance 5_________ a thousand times 6_________ than the Heliosphere.

PART B

rotating plane counterclockwise close orbit dominates

The principal component of the Solar System is the Sun, a G2 main-sequence star that contains 99.86 percent of the system's known mass and 1___________ it gravitationally. The Sun's four largest orbiting bodies, the gas giants, account for 99 percent of the remaining mass, with Jupiter and Saturn together comprising more than 90 percent.

Most large objects in orbit around the Sun lie near the 2_________ of Earth's orbit, known as the ecliptic. The planets are very 3________ to the ecliptic while comets and Kuiper belt objects are frequently at significantly greater angles to it. All the planets and most other objects 4__________ the Sun in the same direction that the Sun is 5_________ (6____________).

Date: 2015-01-11; view: 904