1 . 听下面一段独白，回答以下小题。
1. How many natural Christmas trees did Americans buy in 2016?

A．Less than 35 million trees.	B．More than 10 million trees.
C．More than 24 million trees.	D．Less than 24 million trees.

2. What happens to most real Christmas trees after the Christmas season?

A．They are grown once again.	B．They are delivered to a tree farm.
C．They are safely stored away.	D．They are thrown away.

3. What happens to most artificial Christmas trees after the Christmas season?

A．They are moved to a landfill.	B．They are reused next year.
C．They are cut into pieces.	D．They are exchanged for real trees.

2 . 听下面一段独白，回答以下小题。1.

A．The plants barely grew without radiation.	B．The plants didn’t grow fast enough.
C．The plants looked much stronger.	D．Not all the seeds grew in lunar dirt.

2.

A．Because the astronauts didn’t take care of the dirt.

B．Because the dirt was exposed to radiation and solar wind for too long.

C．Because the dirt stressed the plants the most.

D．Because the Apollo 11 mission was unsuccessful.

3.

A．Because they felt it meaningless to keep the dirt for long.

B．Because they wanted more researchers to do experiments on it.

C．Because they are preparing to send astronauts to the moon again.

D．Because they want astronauts to know more about the moon dirt.