______ the maths problem is difficult, I'll try very hard to work it out. A: Though B.When C. Before D. After

All group members read the instructions first before you act,____you can find[br][/br] below the title.[br][/br] A .what B.when C.which D.That

When people opening up? A: When they feel powerful B: When they are sick C: When they are uncomfortable D: When they are comfortable

When will an offer become effective? A: when it is dispatched B: when it reaches the offeree C: when it is withdrawn D: when it is revoked

When are multimedia tools effective? A: When they are colorful. B: When they enhance your message. C: When they involve technology. D: When they are funny.

When did the author take part in the race? A: When she was a freshman. B: When she was a sophomore. C: When she was a junior. D: When she was a senior.

When can items of clothing be expensive? A: When they are from the supermarket. B: When they are taxed too much. C: When it is a well-known brand or design. D: When they are in the sale.

________ the airport they waved again and again to me. A: When left B: When leave C: When to leave D: When leaving

_____ he came back home that we knew what had happened . A: When it was B: It was when C: Was it when D: When was it

The notice did not tell us _______ the task. A: when to be finished B: when finish C: when finishing D: when to finish