Thoreau's ______is full of eco-wisdom.

A. The gap between its import and export narrowed.
B. The Commerce Department shows great concern.
C. What it imports has outnumbered what it exports.
D. Only the government concerns about the trade deficit.

A. the majority of musicians have been infected with "yellow fever"
B. the fear of yellow fever has made many musicians dare not visit America
C. the fear of terrorists is infectious among people just like the disease yellow fever
D. Americans fear foreigners under the threat of terrorist attack