It is said that ____ young people may lose the abilities to hear after five years if they listen to MP4 players which are too loud for more than five hours a week.

Who helped you repair your bike?—________ ! I repaired it all by myself.

It took him ____ to find the key to the drawer.

Why is the classroom so dirty?—Sorry，sir. Ityesterday, We forgot to do it.

We will celebrate the 90th birthday of the Chinese Communist Party _______June 29th, 2011 in Qinzhou. [ ]