A) Although B) Whether C) Since D) When

A. The epidemic has been brought under control.
B. There are signs of progress in the peace process.
C. Great improvements are being made in its capital.
D. There’s little hope of bringing the conflict to an end.

A. proves to be identical to an epidemic.
B. always follows an epidemic.
C. tends to be widespread and produces more serious disease
D. turns out be fatal to people who get infected

A. it develops side by side with environmental factors
B. it is also affected by environmental factors
C. it is generally accepted to be part of the environment
D. it is a product of man’s biological instincts