<span>Damming a river has a variety of effects on the freshwater ecosystem, more than just altering the flow from A to B. Dams create calm bodies of water, changing overall temperature regimes and sediment transport, leading to conditions which tend to favour generalist species. Loss of specialist species, particularly endemics, changes the community structure and leads to biotic homogenization. A dam will withhold sediment in the reservoir, not just decreasing the amount of substrate available to local freshwater species, but even impacting diadromous, estuarine and marine species much further downstream. The competition between resident species for food and breeding sites will increase as damming isolates populations, and perhaps more importantly, damming completely restricts migratory fish species. Isolation may lead to decreases in genetic diversity and therefore puts species at greater risk from disease. All of these effects may be exacerbated by changes in the surrounding land use. Overall, damming river flow will lead to both a loss of native species, but also an increase in exotic species which are more likely to become established in degraded habitats. For this reason, dams are one of the greatest global threats to freshwater biodiversity.</span>
Number 2, sun increases basically everyday.
The ecosystem will collapse and fail because every species are needed and play a role in the ecosystem.
8. A. Its size
None of the other options would change as a result of just cutting a cork into smaller pieces
9. A. The luggage will be lighter to carry
The weight of water can add up very quickly so when you remove almost 90% of water from a substance, you can substantially decrease the weight
10. A. behind him
The sun is shining on his back so his shadow is in front of him, but if he were to turn around his shadow would still be in the same place in relation to his body
