Complete the following sentences as required（根据所给要求，完成下列句子）：

【1】He’s seldom late for school. （改为反意疑问句）

He’s seldom late for school, _______ _______?

【2】It took her three hours to finish the work yesterday afternoon. （对画线部分提问）

_______ _______ did it take her to finish the work yesterday afternoon?

【3】The hall is very big. It can hold 1,000 people. （合并成一句）

The hall is _______ _______ to hold 1,000 people.

【4】mobile phone, mustn’t, in class, turn on, you, your（连词成句）

_______________________________________________________________.