<span>3. Reduced bone marrow in the spongy bone.</span>
Insects, and some other invertebrates, exchange oxygen and carbon dioxide between their tissues and the air by a system of air-filled tubes called tracheae. Tracheae open to the outside through small holes called spiracles.
I would say the correct answer is B: <span>People tend to overuse or degrade shared resources. It is often not clear how much exploitative pressure a natural resource can sustain before the exploitation becomes unsustainable. So for example, various industries may dispose of waste into a river. The river has a capacity to absorb and clean a certain amount of effluent by natural degradation systems. However, at some critical mass of pollutants, these natural processes are no longer able to function properly, and the river becomes very polluted to a point were the resource cannot be utilised. Monitoring can help to gauge at which point a common resources is becoming unacceptably degraded, and this can guide policy.</span>
I believe that the concept of reaction range proposes that genetics establishes boundaries, whereas environment determines where a person falls within that range. Range of reaction is a concept in psychology, genetics, and related fields that the expressed characteristics or traits of an organism depend on both the genetic characteristics and the environment.
