Humans are the most populous large mammal on Earth today, and probably in all of geological history. ThisWorld Population Day, humans number in the vicinity of7.5to7.6 billionindividuals. Can the Earth support this many people indefinitely? What will happen if we do nothing to manage future pop...
[听力原文]1-5Interviewer: As we all know, more people have been added to the Earth’s population in the 20th century than at any other time in human history. A report shows that "In 1900, just 100 years ago, the world’s human population numbered two billion people. Today, the total...
Like other species, we are the products of millions of years of adaptation. Now we're taking matters into our own hands.
For many thousands of years, there were fewer people roaming the Earth than would live in a mid-sized city today. But this does raise an interesting question, though: over the long arc of human history, how many people have ever lived? The unique and powerful visualization above, from the...
An estimate of the total number of persons who have ever lived on earth depends on two factors: 1) the length of time humans have been on earth; and 2) the average size of human populations at different periods. According to the United Nations' "Determinants and Consequences of Population ...
From 1930 to 1974, theEarth's population doubled again, in just 44 years. But is the human population expected to continue growing at this rate? And is there an upper limit to how many humans our planet can support? Related:What would happen to Earth if humans went extinct?
This is an ancient tree with a history of more than 300 years. After many vicissitudes, part of its trunk has withered. There are two reasons. On the one hand, this ancient tree is old. It is susceptible to the weather. It is easy to get sick. On the other hand, due to human ac...
Knowing just who we share the planet with is of particular concern now because global warming, deforestation and other signs of human development are threatening many species, which may be essential to the functioning of ecosystems or may have inherent value in terms of developing medicines or othe...
according to the China Manned Space website. The amount of urine(尿液)produced and water used by an astronaut per day is about 2 kilograms. The liquids are collected and purified(净化), and then provided to astronauts to d...
Now, the county government on the river, river, etc. were dealt with earth-shaking. There are also many young volunteers who have joined in. Row of garbage, the hospital and some residents to do a series of education and so on. After this treatment, our "Mother River" has restored the...