This problem is too difficult. — You can’t work out the math problem unless you ______ to your teacher carefully. [ ]

Steven, could you help me_______ when the plane will take off on the Internet? -I’m sorry, my computer doesn’t work.

Greatly frightened by the terrible scene, _______.

The news that scientists so far haven’t found out the cause of bird flu discouraged some WHO officials,________?

Life _____ a pig isn’t always perfect.[ ]