He________a wild duck，but he didn't________it.

Two more people in Shanghai have been ________ to be infected with the deadly H7N9 bird flu, local authorities said on Sunday.

 The president spoke at the meeting for nearly an hour without _______ his notes.

There was enough evidence to prove that the explosion in Robinson’s house _______ the leak of natural gas. 

The lower room was in darkness, but by _____ his way he found the bag.