It is these poisonous products _______can cause the symptoms of the flu, such as headache and aching muscles.
| A．who | B．that | C．how | D．what |
20. Don’t be too wordy. Just give me a very _____ answer.
| A．clean | B．clear | C．neat | D．Tidy |
19. The price of the car “Honda” is very _____ and my parents can’t afford it.
| A．cheap | B．high | C．expensive | D．Dear |
18. It is ______ that he has passed the examination, and I am _____ I will pass it too.
| A．certain; certain | B．certain; sure |
| C．sure; certainly | D．certainly; surely |
17. Be when you cross the road.
| A．careless | B．beware | C．careful | D．Carelessness |
16. You cannot be too careful. Which of the following sentences doesn’t have the same meaning of the underlined sentence? _____
| A．You cannot be careful at all. |
| B．You cannot be over careful. |
| C．You cannot be careful enough. |
| D．You cannot take enough care. |