October 24, _____ was the date when America suffered its first stock market crash in history.

A．face insurmountable financial problems.
B．take too much from local residents.
C．increase the need for fire engines.
D．can promote international cooperation.

A．reduce pollution in reserve farmlands.
B．obtain the United Nations' cooperation.
C．learn how local farms are operated.
D．import new breeds of farm animals.