)2.Our English teacher always ------- a smile on her face.

with 是用于修饰前面的主语,比如；the boy with a smile on his face is my brother那个面带笑容的男孩是我的弟弟。 而wear是直接跟在主语后面的谓语,比如；he wears a smile on his face。（他面带微笑） 由此可见,该题应该用"wears”希望对你有帮助^_^~