Question 404
HardOriginal questionWhere does the solar system end? The question is harder than it sounds.
Close in are the Sun, the eight planets and their moons, the belt and many comets. Beyond Neptune, the farthest planet, lies the Kuiper Belt, an almost empty ring around the Sun in which icy bodies, nearly all smaller than Pluto, travel slowly on their orbits. Pluto is the best known of them.
Beyond even that, scientists believe, lies the Oort Cloud. Most of the solar system is flat, like a disk: the planets and the Kuiper Belt all circle the Sun in roughly the same . The Oort Cloud is different. It is thought to be a giant round shell surrounding everything else, like a huge bubble with thick walls. It is made of icy pieces of space the size of mountains, and sometimes larger, and it is where some comets are believed to come from.
The distances are almost impossible to imagine. The Voyager 1 spacecraft, one of the fastest objects ever built, took about thirty-five years just to leave the region where the Sun's is strongest. Reaching the Oort Cloud would take it many centuries more.
"The planets and the Kuiper Belt all circle the Sun in roughly the same plane." Here "plane" means
Show the answer and explanation
Correct answer: B
Explanation
The sentence explains why the solar system is "flat, like a disk": everything moves at about the same flat level.
Worth noting
The common meaning, an aeroplane, is the trap. Here the word means a flat surface or level.
- Concept
- Choosing the right meaning of a word with several senses
- Typical timeTypical
- 45 s
- Your timeYours
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