Many ecologists believe that lots of major species in the world are ______ (濒临灭绝).

A．Most cancer diseases could be treated.
B．Cancer diseases could increase a lot in the next 20 years.
C．Tobacco use is the number one cause of cancer.
D．Colon cancer is especially common in developing countries

A．free natural resources for new use that can vastly improve life
B．replace occupations in Schumpeter’s time by new occupations
C．result in fewer jobs in certain occupations over the long term
D．lead to improved productivity and a stronger economy finally