we were _____ until 5.30 yesterday.(to school/at school)

we were _____ until 5.30 yesterday.(to school/at school)
we were _____ until 5.30 yesterday.(to school/at school)

we were _____ until 5.30 yesterday.(to school/at school)
at school

We were at school until 5:30 yesterday.

at school
因为是
昨天我们待在学校直到5:30
不是
昨天我们去学校直到5:30 (完全不通)