The main idea of the second paragraph is that  

Which of the following is not part of some active regions on the Sun?

However, given that we no longer live in caves and hunt with spears, this ‘best friend’ relationship should be re-examined in light of the many diseases dogs carry and transmit.” The above statement is a statement of

“These formerly pristine regions are rapidly taking on the appearance of overgrown cities, and, in this process, we are destroying these cherished and aesthetic gifts of nature.” An antonym for the word “pristine” is

The main idea of this passage is that  

The example of required courses being offered at conflicting times was used to illustrate  

As used in the last paragraph, the word ” millennium” most nearly means  

Selection 2 Although dogs have long been considered “man’s best friend,” the variety and gravity of the diseases and conditions they can fall prey to—some of which are communicable to humans—suggest this “best friend” relationship should be reconsidered. First of all, dogs are quite prone to physiological maladies involving the skin. No matter what the climate, dogs will have fleas unless some form of systemic pesticide eliminates them. These unavoidable fleas pose a problem for the owners not only in terms of potential infestation and the transmission of tapeworm to humans, but also in terms of conditions such as allergic dermatitis produced by the dog’s reaction to the flea saliva injected with each bite. Susceptible animals lose sections of their coats; in addition to becoming partially bald, they further develop red, irritated, and itchy skin. Also affecting the skin are other external parasites such as mites, which cause mange and mycotic diseases such as ringworm. Second, dogs commonly host a variety of internal parasites; roundworm, hookworm, tapeworm, and heartworm are the most common. Because the last three forms of worms can be fatal to dogs, the animal must therefore be routinely treated with medication designed to purge existing parasites or to prevent their establishment within the animal’s system. Third, without regular vaccinations, dogs can contract life-threatening viruses, the two most well-known being distemper and rabies. Transmitted by airborne pathogens, the highly contagious distemper results in digestive problems, pneumonia, and ultimately in convulsions prior to death. Rabies, a neurotropic virus transmitted through contact with an infected creature’s saliva, attacks the central nervous system, resulting in a series of familiar symptoms. The animal loses appetite, becomes restless, appears uncomfortable, and although thirsty, is unable to swallow because of spasms and paralysis of the throat muscles. Finally, after menacing other animals and children too, the animal dies an agonizingly painful death which is frightening to witness. Fourth, unique to particular breeds are certain physical problems that cause either pain or disability. German shepherds should be x-rayed as puppies to detect hip dysplasia, a potentially crippling deformity of the hips; toy poodles need to be watched for the development of cataracts. Beagles are prone to certain types of tumors. Therefore, in addition to the diseases and conditions most dogs are prone to, some breeds also cause the owners to incur great expense for the treatment of severe physical problems. Are dogs, then, really like friends at all, let alone “best friends”? Their dependent relationship with people most likely originated with early humans needing protection and dogs needing the food humans could provide in return. A bond thus arose based on mutual need. However, given that we no longer live in caves and hunt with spears, this “best friend” relationship should be reexamined in light of the many diseases dogs carry and transmit. A “best friend,” after all, is not someone who will introduce fleas to our homes, or possibly infect our children with worms. Nor does a best friend require medical treatment—at our great expense.

“Also, if a hold is put on a student’s account for an unpaid parking ticket or an overdue library fine, the student cannot register until the hold has been removed.”   The above sentence is a statement of  

The tone of this passage is