• A. about one percent of the total population
• B. to be responsible for childhood leukaemia
• C. an urgent and tough task to be accomplished
• D. less than one third of a million
• E. an expensive cost to be paid
• F. to afford the cost of bone marrow transplantation

Some solvents and building materials are considered ______.

A．Because the H1N1 swine flu virus spreads rapidly.
B．Because there is a flu pandemic in the Northern Hemisphere.
C．Because the doctors always try to diagnose their patients as quickly as they can.
D．Because the doctors have phones ringing, consultants calling, computer screens flashing all the tim

A．Right
B．Wrong
C．Not mentioned