costs mean they are doing so for shorter periods. The rise of "city break" has increased tourist numbers."Too many people do the same thing at the exact same time." says Xavier Font, a professor at the University of Surrey, "For locals, the city no longer belongs to them."

What makes the problem worse is Airbnb, which has made it more convenient for tourists to find accommodation in their destination but adds to residents' headaches. Those permanent citizens who share their apartment blocks with Airbnb hosts have lost their patience, "No longer do we have to share the streets with tourists, and we have to share our own buildings!" To ease the jam around the main attractions, many cities are taking immediate action. Venice is proposing a new concept of "Detourism": sustainable travel tips and alternative routes for exploring a different Venice. A greater variety of guidance for future visitors-ideas for what to do in off-peak seasons, for example, can guide them from overcrowded landmarks. Repeat visitors can not only have a better sense of the culture but also can integrate themselves with residents of the cities better.

28. When faced with tourists and residents' battle, local authorities are________.

A. in panic B. at peace C. in a dilemma D. at ease

29. What may the rise of "city break" lead to?

A. Locals' quality of life improving.

B. Tourist cities being overcrowded.

C. Tourist numbers decreasing.

D. Travelling costs rising.

30. What is Airbnb in the third paragraph?

A. A map for repeat tourists.

B. A city with many tourists.

C. An alternative route for exploring.

D. A website with homestay information.

31. Under the guidance of Detourism, which of the following should be encouraged?

A. Developing a city break in on-seasons.

B. Attracting more first-time visitors.

C. Shifting visitors from busy attractions.

　　D. Reducing repeat tourists.

　　　　　　　　　　　　　　　　　　　　D

Run out of cooking oil or need some dressing for your salad？The solution may be insects from your backyard！Scientists are turning insects into a source of healthy oil. Even though insects are a food source in some parts of the world，to many people，the thought of eating them is very disgusting.

"In the western countries，there is no culture of eating entire insects，so when the idea is to use the protein in powder as an ingredient，people might tend to receive this protein better even if they cannot see it，"said researcher Daylan Tzompas­Sosa，Wageningen University，Netherlands."There are many uses for the oil in general，but we are investigating the use of these oils for a food，as a food ingredient."

The Mexican researcher，working in the Netherlands，said insects are a great source of