A.The harder
B.Harder
C.The hardest
D.Hardest

A.black new wool
B.black wool new
C.new black wool
D.new wool black

A.had improved
B.has improved
C.is improving
D.improved

A.Because
B.Because of
C.In spite of
D.Although

A.future
B.involve
C.prospect
D.guidance

A.motivate
B.furniture
C.advantage
D.ambulance

A.famous
B.enormous
C.dangerous
D.cautious

A.the number of beverage makers
B.the average age of the consumers
C.the mixture of various ingredients
D.natural chemicals in a person's body

A.reasonable
B.unlikely
C.typical
D.impossible

A.Types of Power Plants
B.Electricity: Harmful Effects on Our Life
C.How to Produce Electricity
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