-<span>- </span><span>It is considered to </span>be<span> the link between the lobe-finned fishes and early ... Climate and</span>geography<span> ... </span>Sea<span> levels were high with </span>much<span> of western North </span>America<span> under water. ... By the mid-Devonian, the </span>fossil record<span> shows evidence that there ... Plants, which had begun colonizing the land</span>during<span> the Silurian ...</span>
The answer is a. the ureters. The ureter is a tube that
carries urine from the kidney to the urinary bladder. There are two ureters, the
upper half of the ureter is located in the abdomen and the lower half is
located in the pelvic area. One attached to each kidney.
Surface mines, in metallic mining called open pits are used because they are much more economical for large low grade deposits in which the mineralization as in copper is widely disseminated and needs a bulk mining method such as an open pit.The size is usually numbered in say approximately 50 million to say well over a billion tonnes (metric tons) and underground mining methods mostly could not move this amount of material. Electric shovels and trucks up to or greater than 200 tonnes per truck are used to move this material and it is not uncommon to move 300,000 tonnes per day.
Underground is much more labour intensive and much more expensive so needs a high grade orebody. An open pit can do a lot to preserve the environment by reclaiming the waste dumps ie re-sloping and planting grass for the deer. Also, open pits are no hunting areas so allow a safe haven for large mammals like the moose in Canada.
