Professor Smith, along with his assistants, on the project day and night to meet the deadline.
| A．work | B．working |
| C．is working | D．are working |
—Believe it or not, I have met him before.
—No kidding? ________ you've never mentioned it?
| A．What for | B．How come |
| C．How about | D．What if |
—What's the capital of Bhutan?
—________ Let's go online and find it out.
| A．You bet! |
| B．Give me a break! |
| C．Guess what! |
| D．You've got me there! |
—I hear Kris had an accident as he was riding his bike to school yesterday.
—________？ He is always so careful when he is riding.
| A．What for | B．How come |
| C．Why that | D．So what |
—Hello, Mrs James. Is Sally at home? I want to play badminton with her.
—________. She's gone for a walk across the fields.
| A．I'm sorry | B．Hold on |
| C．No problem | D．Forget it |
（）— You know, I met my girlfriend’s parents for the first time only yesterday.
— ________? I thought you’d met them before.
| A．So what | B．Pardon |
| C．Really | D．What for |