Hello! I'm very glad to see you. When_________ you_________ here? A: did; arrive B: will; arrive C: have; arrived D: are; arriving

When do people open up?: When they are comfortable|When they are sick|When they are uncomfortable|When they feel powerful

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 A: when it is dispatched B: when it reaches the offeree C: when it is withdrawn D: when it is revoked

Can you tell _______?: when did it happen|when it happened|when it was happened|when was it happened

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.

【单选题】______ the meeting is not decided yet. A. When hold B. When to hold C. When to be held D. When held

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