下列词语中划线字读音无误的一项是（    ）

秋天的早晨，山区公路上容易出现大雾，影响行车安全。从物理学角度看，雾是由下列哪种物态变化形成的（  ）

根据句意，选用所给词的适当形式填空
country     twelve       they         west       happy    
____ What do you want to buy for his ____________ birthday？A toy car.
____ We own the blue house while the yellow one is _______.
____ To eat in a ___________ restaurant is quite different from in a Chinese one.
____ China is one of the biggest _____________in the world.
____ How _________ the children are singing and dancing in the classroom.