Выберете правельный ответ 1 who at the zoo last sunday? a) were d) is c) was 2 they at school. a) were d) is c) was

1-с, т.к. после who ставится is, но т.к. есть last Sunday как показатель времени ставим was. 
2-а, т.к they-множественное число, из предложенных вариантов подходит только а)) 

1)Who was at the zoo?

2) They were at school