Protecting the earth is not ____ to be left to the government．Everybody should be concerned．

The saying “Old friends and old wine are best” means the things and people ____ we know are better than the unfamiliar.

 New words selected by the dictionary are closely linked to social phenomena. Instead of being merely words, they are ________ cultural symbols.

Until he told me yesterday,I knew______of what had happened to him .

--- Hi, Anne. Which of the two paintings on the wall do you prefer?--- Actually I don’t like         . Let’s take a look at other paintings.