由∠1+∠2=90 °，∠3+∠4=90 °，∠1=∠3，得∠2=∠4，其理由是（ ）．
等角的余角相等
These two words are different _______ each other in spelling while they are similar ______ each other in pronunciation.
A．from; to
B．from; as
C．with; like
D．with; to
三同时环保设施是指生产设备同时设计、同时施工、同时使用。
