A sheet of metal was shaken to ________ the sound of thunder.

A．largely
B．really
C．merely
D．rarely

A．Insects have developed some sort of resistance to man-made poisons.
B．Insects have been eating plants for about 250 million years.
C．Farmers sometimes use a combination of two or three insecticides at once.
D．New insects mate with insects which survived from a certain kind of insecticide.