Scientists are convinced __________ the positive effect of laughter _________ physical and mental health.
| A．of; at | B．by; in |
| C．of; on | D．on; at |
Upon reading the notice all the staff of the company stood there, lookingat each other.
| A．no speaking | B．speechlessly | C．speechless; | D．did not speaking |
. It’s illegal for anyone under 21 in the USA, the highest drinking age in the world to buy alcohol, and stores or restaurants caughtalcohol to people under the legal age will involve
their licenses.
| A．to sell; to lose | B．to sell, losing | C．selling; losing | D．sold; lost |
Do take each subject seriously in college and even though you learn isn’t important for your life, the learning skills you acquire will be something to be cherished forever.
| A．when | B．where | C．which | D．what |
Robert is said abroad, but I don’t know in which country he is.
| A．have been studying | B．to have been studying | C．have studied | D．to have studied |
The longest bridge linking Hongkong to Chinese mainland at Zhuhai and Macao in a giant Y- shape, is due to be completed by 2015 and to be in use for 120 years.
| A．will be expected | B．is expecting | C．is expected | D．was expected |