The Solar System may be defined as consisting of all those objects that are governed by the Sun's gravitational field. Other effects arising (1) ... the proximity of the Sun could equally (2) ... be used as criteria, such as radiation pressure or interaction with the solar wind. (3) ... any of these definitions the Solar System extends (4) ... to a distance of about two light-years; the closest star, Proxima Centauri, (5) ... lying at a distance of slightly more than four light-years.
Our knowledge of this region of space certainly does not reach as far as this, (6) ... , because the most distant Solar-System objects that we know about, the comets, seem to originate at a distance of no more than 50,000 astronomical units, or less than a third of the total distance. (7) ... for the other Solar-System bodies known to us, they lie at distances of less than a few hundred AU. Our study is therefore confined (8) ... what is primarily the central region of the Solar System.
|VERB + PREPOSITION||ARISE FROM|
|To happen as a result of a particular situation:
Did anything interesting arise from the meeting.
|Could/may/might well => used to say that something is likely to happen or is likely to be true:
It could well be that the plane is delayed.
|Because of the situation that exists:
With Gina away there's more room in the room.
|VERB + PREPOSITION||EXTEND OUT|
|To continue for a particular distance or over a particular area:
Extending out over an existing part of your property is a great idea.
|Used as the object of a verb or preposition to refer to something that has already been mentioned:
History keeps repeating itself.
|Showing how a sentence is related to what has already been said:
This is an extremely dangerous disease which is, however, easy to treat.
|With regard to:
As for Alex, he was happy enough to spend all day in the garden.
|ADJECTIVE + PREPOSITION||CONFINED TO|
|To exist in or affect only a particular place or group:
The risk of infection is confined to medical personnel.