Biological diversity has become widely recognized as a critical conservation issue only in the past two decades. The rapid destruction of the tropical rain forests, which are the ecosystems with the highest known species diversity on Earth, has awakened people to the importance and fragility of biological diversity. The high rate of species extinctions in these environments is jolting, but it is important to recognize the significance of biological diversity in all ecosystems. As the human population continues to expand, it will negatively affect one after another of Earth's ecosystems. In terrestrial ecosystems and in fringe marine eco common problem is habitat destruction. In most situations, the result is irreversible. Now humans are beginning to destroy marine ecosystems through other types of activities, such as disposal and run off of poisonous waste; in less than two centuries, by significantly reducing the variety of species on Earth, they have irrevocably redirected
the course of evolution.
Certainly, there have been periods in Earth's history when mass extinctions have occurred. The extinction of the dinosaurs was caused by some physical event, either climatic or cosmic. There have also been less dramatic extinctions, as when natural competition between species reached an extreme conclusion. Only 0.01 percent of the species that have lived on Earth have survived to the present, and it was largely chance that determined which species survived and which died out.
However, nothing has ever equaled the magnitude and speed with which the human species is altering the physical and chemical world and demolishing the environment. In fact, there is wide agreement that it is the rate of change humans are inflicting, even more than the changes themselves that will lead to biological devastation. Life on Earth has continually been in flux as slow physical and chemical changes have occurred on Earth, but life needs time to adapt-time for migration and genetic adaptation within existing species and time for the proliferation of new genetic material and new species that may be able to survive in new environments.

Australians place a high value on independence and personal choice. This means that a teacher or course tutor will not tell students what to do, but will give them a number of options and suggest they work out which one is the best in their circumstances. It also means that they are expected to take action if something goes wrong and seek out resources and support for themselves.
Australians are also prepared to accept a range of opinions rather than believing there is one truth. This means that in an educational setting, students will be expected to form their own opinions and defend the reasons for that point of view and the evidence for it.
Australians are uncomfortable with differences in status and hence idealize the idea of treating everyone equally. An illustration of this is that most adult Australians call each other by their first names. This concern with equality means that Australians are uncomfortable taking anything too seriously and are even ready to joke about themselves.
Australians believe that life should have a balance between work and leisure time. As a consequence, some students may be critical of others who they perceive as doing nothing but study. Australian notions of privacy mean that areas such as financial matters, appearance and relationships are only discussed with close friends. While people may volunteer such information, they may resent someone actually asking them unless the friendship is firmly established. Even then, it is considered very impolite to ask someone what they earn.

While TikTok can be fun and entertaining, there are a number of dangers that come with using TikTok. (42)______, it's so important for parents to set up parental controls on the app. By doing so, you can help keep your children safe while they use TikTok.
One of the risks of TikTok is that it can be highly (43)_______ If left unchecked, kids can easily spend hours on the app, which can interfere with their everyday lives. Parental controls can help parents limit their child's screen time on TikTok to a healthy amount. This can help kids balance their use of technology with other activities, such as homework, outdoor play, and socializing with family and friends. (44)_______ reason to set up parental controls on TikTok is to block inappropriate content. The app's algorithm can (45)_____ users to mature content that is not appropriate for children or teenagers.
Parental controls can help parents block this type of content from being displayed in their child's feed. This can help protect kids from seeing videos (46)_________ are too violent, sexual, or otherwise age inappropriate.