Задать вопросы 1. his parents work at a plant.( where. who) 2. my sister studies english at school.(what language) 3. he cleaned the blackboard after lesson.(when. who) 4. he went to work in the afternoon.(where. disjunctive) 5. she will come back at 3 o clock. (when. alternative)

1 who works at a plant? Where do his parents work?
2 What language does my sister study?
3 Who cleaned the blackboard after lesson? When did he clean the blackboard?
4 Where did  he go to work? He went to work in the afternoon(не правильно, посмотрите) didn*t he?
5 When will she come back ? Will she come  back at 3 or at 5 o*clock ?