Finding information in today’s world is easy, but the ______ you are likely to face is how you can tell whether the information you get is useful or not. 

The people from the south enjoy the________in the north during the winter because they have never seen snow before.

Liu Xiang achieved his __________ to become the first man to cover the 110-meter hurdles in less than 12.91 seconds.

In 21st century universities in the US, there is little room for traditional literature because students feel a lot of         to study science.

The foreign teacher Mr. Halt has a strange way of writing. Here’s a notice from him, but no clear ______ of what he has written can be made at all.