I just don't understand_____________ that prevents so many Americans from being as happy as one might expect.
| A．why it does | B．what it does |
| C．what it is | D．why it is |
He is__ doctor at all. Don’t trust him.
| A． no | B． not | C．any | D．a |
He is a member of our ___ .
| A．brain power | B．brains power | C．brain powers | D．brains powers |
----Sorry, Michelle is a little shy.
----Never mind, I ____ be that way when I was ___ her age.
| A．would, at | B．used to, × | C．would, × | D．used to, at |
----How do you deal with disagreements between the company and the customers?
----They key____ the problem is to meet the demand ___by the customers.
| A．to solving; making | B．to solving; made |
| C．to solve; making | D．to solve; made |
______a fire, hotel guests are asked to remain calm.
| A．As a result of | B．In the event of | C．By reason of | D．In the time of |