题目内容：

About three decades ago, China was known as the "Bicycle Kingdom". But later on, bikes were replaced by their fuel-powered competitors.

But recent months have seen a recovery of the humble bike across China, with an increasing number of people choosing cycling instead of driving to schools, to workplaces or to do sightseeing. The introduction of bike-sharing schemes, pioneered by start-ups like Ofo and Mobike, has brought the trend to a new level.

People can unlock the shared bikes by simply using their smartphone. The bikes are equipped with GPS and can be left anywhere in public for the next user. They're popular among many Chinese people as they provide an effective solution to the "last mile" problem,which refers to the final leg of a person's journey.

" In places where the subway doesn't extend, where it's difficult to change from one kind of transport to another, it's so easy to get where you want to go with Mobike," Hu Hong,29,told AFP. She pedals(骑车)to her Shanghai real-estate job.

However, the schemes have also led to problems such as illegal parking, vandalism(故意毁坏) and theft. Last month，two nurses in Beijing were placed under administrative punishment for five days for putting locks on two shared bikes. And in December, a man who stole a shared bike was sentenced to a 3-month detention(拘留)，and fined 1 ,000 yuan by the Shanghai Minhang People's Court.

" Bike-sharing is a greener method of transportation and provides a user-friendly experience，"said Liu Xiaoming，vice-minister of transport.

" But it's a combination of online and offline business. Operators are usually strong in online services, but lack offline business experience, which causes problems."

Now, Chinese service operators are trying to solve the problems. For example, a bike- sharing company called Mobike sets a 100-point credit score for each user, with points taken in the case of bad behavior. Once a score drops below 80，bike rental is increased to 100 yuan per 30 minutes, up from 0.5 - 1 yuan.

1.Which of the following belongs to the "last mile" problem?

A. Missing the business plane for the traffic jam.

B. To get to somewhere the subway can reach.

C. Having troubles in changing from bus to taxi.

D. To remove the last rock in the way.

2.What reason causes many problems in bike-sharing?

A. Some people make damage to the bikes on purpose.

B. Operators lack offline business experience.

C. The bike-sharing business is too complicated to run.

D. There are no relative laws on this business.

3.Why are the bike-sharing systems popular?

A. They are very effective.    B. They can be picked up anywhere.

C. They are equipped with GPS.    D. They help solve the last mile problem.

4.What's the best title for this passage?

A. Bickes Pedaling Back Into Styles

B. A New Way of Transportations

C. Riding a Mobicycle for Free

D. Bicycle Kingdom Became Famous Again