New bike-on-demand services give a new dimension to urban sharing economy. In the 1980s, a bicycle, a radio and a sewing machine were considered as the top three _______ for Chinese couples. At the time, China was the “Kingdom of Bicycles”—bikes were key to people’s daily transportation. Now, the country _______ the world’s largest automobile market. Yet, ambitious entrepreneurs keep attempting to _______ lost glory to bikes. Their strategy, however, is changing.

GPS-enabled and painted in _______ orange, at least 100, 000 Mobikes are in service in Beijing, Shenzhen, Guangzhou and Chengdu. And with its signature yellow bikes, of now connects’ about 227, 000 bicycles in 21 cities. Newcomers like Hello-bike and Ubike are catching up.

Unlike traditional public bikes that have to be borrowed at and returned to a bike stand after a journey, sharing bikes save people from such troubles. Using an intelligent lock with _______ functions to help users locate and borrow bikes, these smart bicycles can be parked in any public area _______ by a local government. Normally, they can be unlocked in seconds by simply scanning the _______ QR code on each bike. Suitable for both enthusiastic cyclists and daily short-distance commuters, the round-the- clock, hourly-charging service is obviously a (an) _______.

But bike-sharing platforms face grave (严峻的) maintenance and management challenges. Damage to and losses of bikes, along with improper parking, are often reported-despite their owner’ _______ calls for proper, considerate use. Regular disappearance and damage reports have not just __________ extra financial burdens of the bike- sharing companies, but also raised the costs of offering such a service __________ decent customers. Parking in unauthorized areas __________ a challenge to urban management, too.

That some 200 sharing bicycles were impounded (扣留) last month by the urban management authorities in Chengdu for “illegally occupying public space”, however, is not a kind of rule needed. Rather, what local government should do is to adapt to the rising trend of bike sharing, and __________ rules keeping the local conditions and people’s convenience in mind.

Bike sharing services should be welcomed by cities aspiring to promote green transport and reduce vehicle emissions and congestion. The GPS system installed on these bikes can help the service apps easily __________ the unruly (不守规矩的)users, who are less likely to repeat their mistakes if given an official warning by the urban management authorities.

The service apps do have other options besides issuing penalties. Keeping a record of customers using shared bikes and adding it to their credit record would be a(an) __________ attempt, so would recruiting volunteers to supervise and report improper use.

On Monday, two groups of boys had a fight at Southwood High School. The following day, two groups of girls ________ where the boys had left off. In just two days, 23 students were taken to the police office.

So when Craig Lee, a business owner and community activist, was told about the ________ gang (帮派) tensions, he ________ Michael La’Fitte, who had a daughter at Southwood. They held a meeting and the ________ in attendance decided to make their ________ known on campus.

“We’re dads,” said La’Fitte. “The best people to ________ our kids are us.” That’s how Dads on Duty was born to ensure kids’ ________ . They sacrifice their own ________ . Some are fathers of kids at the school, ________ others are uncles, grandfathers and men like Lee, who volunteered to help the youth in his ________ .

Since then, ________ have dramatically declined and gang battles have stopped. “The school has been ________,” said one student. “They ________ with us like we’re their own children.”

But it’s not just cheerful greetings and funny jokes that have ________ Southwood. It’s the Positive Presence Promotion, developed by Dads on Duty, which means getting involved in home lives, engaging in dialogue about gang culture, and, ________ , making sure every kid has an adult they trust to ________ in times of crisis.

The presence of dads is meant to be ________ . One day after school, Dad on Duty Mike Morgan ________ some students wandering outside were waiting for their target of bullying. He found the target and steered (引导) him clear of the area. So to detect such a situation requires dads to be more ________ .

These dads have partnered with fathers in other counties who’ve followed their ________ . As La’Fitte said, “We’d like this to happen in every school.”

Man the Hunter, a key idea in human sciences, proposes that hunting was a major driver of human evolution and that men conducted this activity, leaving women out. It holds that human ancestors had a division of ______, rooted in biological differences between males and females, in which males evolved to hunt and provide, and females tended to children and domestic duties. It assumes that males are ______ superior to females and that pregnancy (怀孕) and child-caring reduce or eliminate (根除) a female’s ability to hunt.

Man the Hunter has dominated the study of human evolution for nearly half a century and spread through popular ______. It is represented in museum displays and textbook figures, Saturday morning cartoons and feature films. The thing is, it’s ______.

Researchers look at the damage on our ancestors’ remains for clues to their ______. Neandertal females and males do not vary in ______ patterns or exhibit sex differences in diseases from repetitive actions. Their skeletons show the same modes of wear and tear. This discovery implies that they were engaging in ______ activities, from hunting large game animals to processing fur for leather.

Observations of recent and contemporary societies provide direct evidence of women ______hunting. Agta people of the Philippines, ______, hunt while pregnant and breastfeeding, and they have the same hunting success as Agta men.

A recent study of cross-cultural observational data lasting the past 100 years—much of which was ______ by Man the Hunter contributors—found that women from a wide range of cultures hunt animals for food. 79 percent of the 63 societies with clear descriptions of their hunting strategies reportedly feature women ______. The women are involved in hunting regardless of their childbearing status.

Much about female exercise science and the ______ of prehistoric women remains to be discovered. But the idea that in the past men were hunters and women were not is absolutely ______ even by the limited evidence we have. Now when you think of “cave people”, we hope, you will imagine a(n) ______ group of hunters surrounding a deer or hitting stone tools together rather than a heavy-browed man with a heavy stick over one shoulder. Hunting may have been remade as a ______ activity in recent times, but for most of human history, it belonged to everyone.