The tone of this passage is ______.

A．Because they are afraid of people.
B．Because diseases cost a lot.
C．Because they are afraid of the cutting down of their revenue.
D．Because they are afraid of manufacturers.

A．World governments should conduct serious campaigns against smoking.
B．World governments take timid measures against smoking.
C．Smoking is the most important source of income to many countries.
D．Tobacco industry spends a large sum of money on medical researc