请告诉我为什么选这个选项及为什么其它的选项是不对的呢？
There is a teapot shaped like a China duck, out of _________ mouth the tea is supposed to come.
A which
B whose
C that
D its
答案为B

There is a teapot shaped like a China duck, out of _________ mouth the tea is supposed to come.
A which
B whose
C that
D its


这是一个非限制性定语从句,需要连词,排除D
逗号后的从句是不可以用that,这是要记住的

whose mouth=the mouth of which=of which the mouth两者之间是有一定的关系的
在限制和非限制定语从句中whose+名词作主语或是宾语,在这个结构中whose对名词起限定作用

which不符,无法与mouth 构成关系