(a)   is Mary doing at the moment?

(a)   does the first train arrive every day?

(a)   will be Sports Day be held this year?

(a)   are my socks?

(a)   will the dance performance take place?

(a)   person is Mr Wong, the one with the red or silver tie?

(a)   would you prefer, coke or water?

(a)   is the girl sitting next to you?

(a)   wants some salad?

(a)   iPad is this?

(a)   sweater is this?

(a)   are you late for the online lesson?

(a)   did you talk so angrily?

(a)   did you get to the airport yesterday?

(a)   are you today?

(a)   was your trip last month?

(a)   of your friends is going ice-skating with you?

(a)   is your sister talking to?

(a)   is the progress of the project?