The experiment has（）the possibility of the existence of any life on that planet, but it does not mean there is no life on other planets.

单项选择题Which of the following happened first（）

A. The cougar jumped from the rock.
B. Tom struggled free of his father.
C. Jeb asked Tom to get the knife.
D. Jeb held Tom across his body.

单项选择题How did Jeb try to hold the cougar’ s attention（）

A. By keeping shouting and hitting.
B. By making a wall out of his arms.
C. By throwing himself on the cougar.
D. By swinging his fists at the cougar’ s eyes.

单项选择题What do we know about cougars（）

A. They are afraid of noises.
B. They hesitate before they hit.
C. They are bigger than we think.
D. They like to attack running people.

单项选择题Why did Jeb pull his jacket open when he saw the cougar（）

A. To get ready to fight.
B. To frighten it away.
C. To protect the boy.
D. To cool down.

单项选择题35（）

A.by 
B.till 
C.for 
D.from

单项选择题34（）

A.it 
B.such 
C.something 
D.everybody

单项选择题33（）

A.atmosphere 
B.sympathy 
C.calmness 
D.joy

单项选择题32（）

A.lit 
B.took 
C.burned 
D.cheered

单项选择题31（）

A.chance 
B.gift 
C.moment 
D.reward

单项选择题30（）

A.after 
B.until 
C.when 
D.since