1 . —Earth is ________ only home to everyone.
—Let’s try to make it ________ greener world to live in.

A．a; a

B．a; the

C．the; a

2 . Perhaps there will be no water or air on _________ Earth.

A．a

B．an

C．the

D．/

3 . It was ________ cold winter night and the moon was shining brightly across ________ night sky.

A．a; the

B．a; a

C．the; a

D．a; /

4 . The Grand Canyon is ________ great wonder of ________ natural world.

A．an; the

B．the; a

C．the; 不填

D．a; the

5 . —Do you know anything about ________ Earth?     
—Yes. It provides water and food ________ us.

A．a; for

B．an; with

C．the; for

D．/; with

6 . —Please look at ________ moon in the sky, Lily.
—Wow! It looks like ________ round plate (盘子).

A．a; the

B．the; the

C．the; a

D．a; a

7 . _______ moon goes around ________ earth.

A．The; an

B．A; the

C．An; a

D．The; the

8 . — Look! What’s that moving high up in ________ sky?
— It must be ________ plane.

A．a；the

B．the；/

C．the；a

D．/；a

9 . London is in the south of England and it is on ________ River Thames.

A．a

B．the

C．an

D．/

10 . They are having ________ great time under ________ sun.

A．a; an

B．an; a

C．an; the

D．a; the