例句與造句

1. The shoulder joint is the only functional joint in all cetaceans except for the Amazon river dolphin.
2. The hypobranchials are attached at their lower ends at an angle of 21, 5?via a functional joint that possibly served to increase the gape of the mouth, to about two feet.
3. It's difficult to find functional joint in a sentence. 用functional joint造句挺難的