was, were 구분하는 문제입니다...

다음 문장에 들어갈 괄호의 동사의 형태 알려주세요..

1) last monday, the design for the new school uniforms was ( show) to the students.
2) the new uniforms (was / were ) designed by jimim kim.
3) the new jackets (has / have ) two buttons instead od three buttons.