I don’t know for sure how many of you would like to settle here ---- it is a(n) ______ of   personal preference.

The police always take ________ of dogs’ sharp sense of smell to search for the survivors in the earthquake.

After the flood, what the local government did first was to provide _____ for the homeless families．

(2014·福建省普通高中质量检查)Because of H7N9 bird flu，all the chicken markets in Shanghai  have been closed and won’t open until further________.

Ancient Greeks were responsible for many of the _______ in science and other fields.