A.the cells and tissues of the brain.
B.the resident memory.
C.the mobility of the mind and the body.
D.the arteries of the brain.

A.only use mobile phones in medical emergencies.
B.keep off mobile phones regularly.
C.never use mobile phones in all cases.
D.only use mobile phones in urgent cases.

A.their invisible rays.
B.their raiding power.
C.their radiant light.
D.their power of attraction.

A.abandoned his family.
B.could no longer think by himself.
C.had a problem with memory.
D.had a serious problem with mobility.

A.Mobile Phones: A Must of Our Time
B.The Reason Why Mobile Phones Are Popular
C.The Way Mobile Phones Work
D.Technological Innovations and Their Price

A.certainly
B.privately
C.obviously
D.possibly

A.change their user’ temperament
B.cause some mental malfunction
C.change their users’ social behavior
D.damage their users’ emotions

A.they are indispensable in everyday communications.
B.they make them look more stylish.
C.they keep the users alert all the time.
D.they cannot be replaced by regular phones.

A.if
B.therefore
C.so
D.as though

A.barely
B.hardly
C.sparsely
D.scarcely