The earth is our home so it _______ well.

A.Create an environmental protection model city, and build a green ecological hom

B.Build a model city for environmental protection and make our home green.

C.Make a Green City—Reduce, Reuse, Recycl

A.我们的产品在国内外享有良好的声誉，所以其需求量正在逐年增加。

B.由于我们的产品质量非常好，它们在国内外的需求量一年超过一年。

C.因为国内外对我们产品的需求址都很大 , 所以我们每年都扩大生产。

(That) the sun (but) not the earth (is) the center of our planetary system (was) a difficult concept to grasp in the Middle Ages.

A．That

B．but

C．is

D．was

The article suggests that______.

A. our earth exists before the sun

B. how space formed

C. no one knows where the earth comes from

D. our earth used to be part of a high mountain on the sun

A.A.receives

B.B.accepts

C.C.admits

D.D.offers

The atmosphere again acts our protective blanket on _____

[A] stars

[B] sun

[C] earth

[D] space

_______ from space, we can find that our earth looks like a“blue planet”.

A、Seen

B、Seeing

C、Having seen

D、To see

A.a, a, a, a

B.the, the, the, the

C./,/,/,/

D.an, an, an, an

makes our environments tolerable and some ultraviolet rays (紫外线) penetrate the ____

[A] environment

[B] space

[C] atmosphere

[D] earth

A.a lion in the way

B.the salt of the earth

C.skin of our teeth

D.a piece of cake