A.Guidebooks Flourishing Despite the IT Revolution?
B.Enjoying a Paperless Holiday
C.Guidebooks in Decline: What's the Future?
D.Guidebooks on the Brink of Extinction

A.Don't mention it
B.That's nice of you to say so
C.I'd love it
D.I couldn't agree more

A.No way, sorry.
B.Just round the corner over there.
C.Look it up in a dictionary!
D.There's no traffic near here.

A.inequalities
B.developments
C.advantages
D.outcomes

A.most of the world's urban expansion is taking place in slums
B.too many people hope for a better life in cities
C.employment opportunities in cities are greater
D.poverty cannot be eliminated thoroughly

A.NaAlO2.
B.AlCl3.
C.Al2O3.
D.Al2(SO4)3.

A.Na, K.
B.Be, Na.
C.Cr, K.
D.Na, Fe.

A.Na.
B.Ca.
C.Al.
D.Fe.

A.Mg2+.
B.Ag+.
C.Fe2+.
D.Cr2+.

A.Ca.
B.Na.
C.Cu.
D.Al.