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