The two researchers originally set out to study the zebras in Africa and discovered a new species of tiger ______.
| A．by chance | B．in addition |
| C．by nature | D．in need |
As the quality of the city’s air continues to give rise to ______, the residents are encouraged to set off fewer fireworks.
| A．descriptions | B．comparison | C．concerns | D．emergency |
About 300,000 people climb Mount Fuji each year, according to the Japan National Tourism Organization, ______ crowding into a brief summer climbing season.
| A．most of them | B．most of whom | C．most of which | D．most of where |
A survey says what parents say and do in daily life usually has a(n) ______ influence on their child.
| A．logical | B．permanent | C．avoidable | D．beneficial |
In Hong Kong the eighth day of the fourth lunar month is a special day, called Bun Festival, ______ many residents and travelers gather at Cheung Chao island to celebrate a unique tradition.
| A．which | B．when | C．while | D．as |
Jiaxing is a small city. Therefore, to ______ the flow of traffic, the government has decided to broaden some main streets.
| A．speed up | B．build up | C．put up | D．come up |