What is the main topic of this lecture？
A. The cause of marine mammal deaths.
B. How marine mammals communicate.
C. A comparison of dolphin and whale language.
D. The effects of sonar on mammal communication.
【B4】
A. with
B. to
C. of
D. for
What does" belief" mean to the author？
A. Faith.
B. Trust.
C. Security.
D. Hop
A．The woman's source of information is reliable.B．He didn't enjoy taking history with
A. The woman's source of information is reliable.
B. He didn't enjoy taking history with Dr. Parker.
C. He thought Dr. Parker's tests were easy.
Dr. Parker is no longer teaching history.
微信支付 
支付宝支付