1.答案应该是:both...and...,当然也可以说:as well as,not only...but also...
either...or...的意思是“或者/要么...,或者/要么...”.
2.如:
1)He is both tall and strong.
= He is tall as well as strong.
= He is not only tall but also strong.
他既高又健壮.
2)He is either a teacher or a college student.
他是一个老师或者大学生.