A．Because he needs to book a flight．
B．Because he intends to travel in the country．
C．Because he hopes to return to the U．S．A.
D．Because he wants to get his．backpack back.

A．Find information on the U．S．Department of State website.
B．Prepare some extra money for the emergency passport.
C．Contact her later for the necessary documents.
D．Come to the consulate immediately for protection.

A．Some tissues are more vulnerable to cancer.
B．Most types of cancers have been caused by unhealthy lifestyle.
C．Some of the cancers have no specific causes.
D．Smoking is a major risk factor for cancer.