For many of us, our closest meeting with wild animals is at a zoo. These places allow us to observe the behaviours and characteristics of amazing creatures. It's an enjoyable and educational experience for us, but is it the best environment for the animals? A long time ago, people could only see wild animals as stuffed dead exhibits in a museum. Later, live animals were caught by explorers, brought home and put on show to the public in zoos—animal protection was not a priority. But modern zoos and wildlife parks have transformed the conditions and environments for animals, making bigger enclosures（围场）, removing bars, and, to some extent, copying their natural habitats. 

Some people have questioned the cruelty of keeping animals and using them just for entertainment, but zoos are keen to show they are here to help wildlife by educating us about protection. In the UK, the introduction of The Zoo Licensing Act 1981 also required zoos to educate the public. Well-managed zoos are now also involved in supporting and funding protection programmes. 

Probably the biggest claim from zoos today is that they help to protect species that are under threat in the wild due to climate change. Robert Young, Chair in Wildlife Protection at Salford University says: "We wouldn't have a lot of different species today if it wasn't for zoos." Some zoos have breeding （繁殖）programmes which help to preserve the future of species. Actor Leonardo DiCaprio recently praised Chester Zoo in the UK for its protection work. It brought a rare fish species back from the dead after breeding and releasing a school of golden fish back into their native river.

While the debate about having zoos continues, new opportunities to meet wildlife are being explored, such as using virtual reality, and Jon Coe, a zoo designer, told the BBC: "Taking a walk through a group of elephants in the Serengeti, I think, is going to be possible pretty soon."

When international aid is given, steps must be taken to ensure（确保）that the aid reaches the people for whom it is intended. The way to achieve this may not be simple. It is very difficult for a nation to give help directly to people in another nation. The United Nations Organization（UNO）could undertake to direct the distribution of aid. Here however rises the problem of costs. Also tied with this is time. Perhaps the UNO could set up a body of devoted men and women in every country who can speedily distribute aid to victims of floods and earthquakes.

More than the help that one nation can give to another during a disaster, it would be more effective to give other forms of help during normal times. A common proverb says, "Give me a fish and I eat for a day, teach me to fish and I eat for a lifetime." If we follow this wise saying, it would be right to teach people from less developed nations to take care of themselves. For example, a country could share its technology with another. This could be in simple areas like agriculture or in more complex areas like medical and health care or even in building satellites. Even small country is able to help less developed nations. Sometimes what is taken for granted, like the setting up of a water purification plant or the administration of a school, could be useful for countries which are looking about to solve common problems. It does not cost much to share such simple things. Exchange students could be attached for a number of months or years and learn the required craft while on the site. They can then take their knowledge back to their homelands and if necessary come back from time to time to clear doubts or to update themselves. Such aid will be truly helpful and there is no chance of it being temporary or of it falling into the wrong hands.

Many countries run extensive courses in all sorts of skills. It will not cost much to include deserving foreigners in these courses. Besides giving effective help to the countries concerned, there is also the build-up of friendships to consider. Giving direct help by giving materials may be effective in the short run and must continue to be given in the event of emergencies. However, in the long run what is really effective would be the sharing of knowledge.

Have you ever paid for educational podcasts (播客)or live videos? Ask some people and most of them will say yes. "Pay-for-knowledge" has been more and more fashionable these years. The contents of these "pay-for-knowledge" products are from language learning to gardening or baby-caring. Everything you think of can be found online at this moment. "Pay-for-knowledge" is on the rise(兴起).

Why is "pay-for-knowledge" industry developing so rapidly? First, its development is based on the Internet. With a fast network and a smartphone, anyone who has passed the identity(身份) check can be an online teacher, and anyone with an online account can buy "pay-for-knowledge" products that he or she wants at an affordable price. Second, people are afraid to miss any information. On one hand, people hope for more useful information.           

On the other hand, such information is usually at the hands of experts (专家) who serve well-known companies and universities. Moreover, the need to learn new skills in today's job market also pushes people to learn on such educational podcasts.

The industry of "pay-for-knowledge" has proved to be lucrative. It promises possibilities of turning information into money. It is good for the development of our country and it can help sellers make lots of money. Besides, buyers can enjoy self-growth from it. What's more, this is a reflection(反映)of respect for knowledge and talents.

However, the rapid development of "pay-for-knowledge" has a few problems. For one thing, the market is full of eye-catching words such as "How to be an Industry's Expert in 5 Hours" and "15 Classes to Be a Master of Appreciating (欣赏) Classical Music", which sound like if you pay for it, you are sure to succeed. For another, a large number of customers buy them just for showing off. In fact, those who have really had self-growth after buying online courses may be the kind of people who need them least. In other words, with or without these courses, they can make it anyway, because they are those who have the ability to learn by themselves.

In general, the best is the one that suits you most. "Pay-for-knowledge" may be used as a good start for self-growth. Be careful! Otherwise, your dream of success may not come true.