Many experts think pigs are ______ to train than dogs or cats.

When spring comes, the days get ____ and the nights get _____. 

Now the air in Yancheng is _______ than it used to be . We should do something to stop it .

I can hardly hear you because it’s too noisy here. Please speak _______ .                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            

Do you know of all the words we used in 2011 "hold" became      in China?