3.边界线，边界 n.b _ _ _ _ _ _ _ _
4.永恒的，经久不变的 a.c _ _ _ _ _ _ _ _
5.基础，根据 n.b _ _ _ _ _ _ _ _
6.发射，发动 v.l _ _ _ _ _ _ _ _
7.双胞胎之一 a.t _ _ _ _ _ _ _ _
8.同伴，同事 n.c _ _ _ _ _ _ _ _
9.人类 n.m _ _ _ _ _ _ _ _
10.推测，猜测 n.s _ _ _ _ _ _ _ _
11.吞 v.s _ _ _ _ _ _ _ _
12.不充分的 a.i _ _ _ _ _ _ _ _
13.物质 n.m _ _ _ _ _ _ _ _
14.情况，环境 a.c _ _ _ _ _ _ _ _
15.发生，出现 v.o _ _ _ _ _ _ _ _
16.强烈的 a.i _ _ _ _ _ _ _ _
17.证据 n.e _ _ _ _ _ _ _ _
18.看不见的 a.i _ _ _ _ _ _ _ _
19.宇航员 n.a _ _ _ _ _ _ _ _
20.热带的 a.t _ _ _ _ _ _ _ _
Ⅱ Word Form
1.Supernovae____（report） by astronomers in the seventeenth and eighteenth centuries.
2.Imagine the earth reduced to the size of a marble， but still____（have） the same mass， and you have some idea of the force of a black hole.
3.If one____（make） a journey over the Continents one would find every kind of surface including mountain ranges， plains， and empty areas covered permanently by ice and snow.
4.And astronomers are planning a new observatory to study the individual exploding stars____（believe） to be black holes.
5.Matter from the one which we can see____（pull） towards the companion star.
6.There might be a massive black hole at the centre of our galaxy____（swallow） up stars at a very rapid rate.
7.The most____（convince） evidence of black holes comes from research into binary star systems.
8.They show us a world which operates in a ____（total） different way from our own.
9.The surface of some areas____（consist） largely of high mountains and deep valleys.
10.Our world is the home of a very great many different people-peoples with different____（colour） skins.
Ⅲ Vocabulary and Structure
1.Astronomers and scientists think that a black hole is a region of space （not a thing）____which matter has fallen and____which nothing can escape-not even light.
[A] into into
[B] into from
[C] from into
[D] from from
2.This process of shrinking may be so intense____a black hole results.
[A] whether
[B] what
[C] which
[D] that
3.Binary stars，____their name suggests， are twin stars whose position in space affects each other.
[A] as
[B] that
[C] what
[D] if