He finds it hard to keep _____ with the change of society if he stops learning.
is known to us all, Germany is ______ European country.
The club welcome all new members ________ age.
The nutrients in ________ falls into the ocean quickly become available to other living things.
AIDs is a disease that _______ the body”s immune system. A breaks out B. breaks into C. breaks down D. breaks up
Word came ________ the present would be shown around Zunyi.