Which of the following is true of variable stars?
A.They vary in brightness
B.They rotate around each other.
C.They vary in color.
D.The size of the telescope must vary in order to observe them.

Why does the author write that “stellar astronomy is possible for everyone”?
A.To emphasize that it is easy to become an astronomer
B.To encourage people to try observing stars
C.To show that most people know a lot about stars
D.To explain why astronomy is popular

The word “parameters” in paragraph 1 is closest in meaning to
A.Measurements
B.Laws
C.Categories
D.Numbers

The word “ rudimentary” in paragraph 4 is closest in meaning to
A.Advanced
B.Formal
C.Basic
D.Important

Lewis and Clack had been gone for such long on their expedition that many thought they were dead.
A.Been gone
B.Such
C.Many
D.Were dead

Though it is one of the rarest metals, gold was one of the first to be discover.
A.Though
B.Rarest metals
C.The first
D.Discover

_________(36)
A.announcements
B.positions
C.decisions
D.locations

_________(38)
A.better
B.open
C.difficult
D.worsening

_________(39)
A.motion
B.use
C.sale
D.method

_________(41)
A.by
B.in
C.backwards
D.from