After designing more experiments,they were able to clarify the procedure bees municate information that they use to find and fetch food.
A. by which
B. in which
C. by that
D. for which
网友回答
(答案→)A. by which
B. in which
C. by that
D. for which
解析：by which是介词+which构成的定语从句，表方式。