The word which in the second paragraph refers to _______.

Hummingbirds are small, often brightly colored birds of the family Trochilidae that live exclusively in the Americas. About 12 species are found in North America, but only the ruby-throated hummingbird breeds in eastern North America and is found from Nova Scotia to Florida. The greatest variety and number of species are found in South America. Another hummingbird species is found from southeastern Alaska to northern California. Many hummingbirds are minute. But even the giant hummingbird found in western South America, which is the largest known hummingbird, is only about 8 inches long and weighs about two-thirds of an ounce. The smallest species, the bee hummingbird of Cuba and the Isle of Pines, measures slightly more than 5.5 centimeters and weighs about two grams. Hummingbirds' bodies are compact, with strong muscles. They have wings shaped like blades. Unlike the wings of other birds, hummingbird wings connect to the body only at the shoulder joint, which allows them to fly not only forward but also straight up and down, sideways, and backward. Because of their unusual wings hummingbirds can also hover in front of flowers so they can suck nectar and find insects. The humming- bird's bill, adapted for securing nectar from certain types of flowers, is usually rather long and always slender, and it is curved slightly downward in many species. The hummingbird’s body feathers are sparse and more like scales than feathers. The unique character of the feathers produces brilliant and iridescent colors, resulting from the refraction of light by the feathers. Pigmentation of other feathers also contributes to the unique color and look. Male and female hummingbirds look alike in some species but different in most species; males of most species are extremely colorful. The rate at which a hummingbird beats its wings does not vary, regardless of whether it is flying forward, flying in another direction, or merely hovering. But the rate does vary with the size of the bird - the larger the bird, the lower the rate, ranging from 80 beats per second for the smallest species to 10 times per second for larger species. Researchers have not yet been able to record the speed of the wings of the bee humming-bird but imagine that they beat even faster. Most hummingbirds, especially the smaller species, emit scratchy, twittering, or squeaky sounds. The wings, and sometimes the tail feathers, often produce humming, hissing, or popping sounds, which apparently function much as do the songs of other birds. 

According to the passage, where are hummingbirds found?

According to the passage, red algae is________.

The author indicates that a hummingbird’s wings are different from those of other birds because .........

According to the passage, what causes the unique color and look of hummingbirds?

Which of the following is NOT true about algae?

The word “minute” in the second paragraph is closest in meaning to_______.

The author indicates that the ruby-throated hummingbird is found _______.

What can the word invokes be best replaced by?

What does the author imply about the rate hummingbirds’ wings beat?

The word "pigment" at the end of the first paragraph means________.

Green algae is generally found________. 

Algae is a primitive form of life, a single-celled or simple multiplecelled organism that is able to conduct the process of photosynthesis. It is generally found in water but can also be found elsewhere, growing on such surfaces as rocks or trees. The various types of algae are classified according to pigment. Blue-green algae, or Cyanophyta, can grow at very high temperatures and under high-intensity light. This type of algae is the oldest form of life with photosynthetic capabilities. Fossilized remains of blue-green algae more than 3.4 billion years old have been found in parts of Africa. Green algae, or Chlorophyta, is generally found in fresh water. It reproduces on the surfaces of enclosed bodies of water such as ponds or lakes and has the appearance of a fuzzy green coating on the surface of the water. Brown algae, or Phaeophyta, grows in shallow, temperate water. This type of algae is the largest in size and is most recognizable as a type of seaweed. Its long stalks can be enmeshed on the ocean floor, or it can float freely on the ocean's surface. Red algae, or Rhodophyta, is a small, delicate organism found in the deep waters of the subtropics. This type of algae has an essential role in the formation of coral reefs: it secretes lime from the seawater to foster the formation of limestone deposits.

What is the author's main purpose?

Which of the following properties is NOT mentioned as protected by copyright?

Why does the couple exchange garlands?

 Although the purpose of artistic property is usually public use and enjoyment, copyright establishes the ownership of the creator. When a person buys a copyrighted magazine, it belongs to this individual as a tangible object. However, the authors of the magazine articles own the research and the writing that went into creating the articles. The right to make and sell or give away copies of books or articles belongs to the authors, publishers, or other individuals or organizations that hold the copyright. To copy an entire book or a part of it, permission must be received from the copyright owner, who will most likely expect to be paid. Copyright law distinguishes between different types of intellectual property. Music may be played by anyone after it is published. However, if it is performed for profit, the performers need to pay a fee called a royalty. A similar principle applies to performances of songs and plays. On the other hand, names, ideas and book titles are excepted. Ideas do not become copyrighted property until they are published in a book a painting or a musical work. Almost all artistic work created before the 20th century is not copyrighted because it was created before the copyright law was passed. The two common ways of infringing upon the copyright are plagiarism and piracy. Plagiarizing the work of another person means passing it off as one’s own. The word plagiarism is derived from the Latin plaglarus, which means “abductor”. Piracy may be an act of one person, but, in many cases, it is a joint effort of several people who reproduce copyrighted material and sell it for profit without paying royalties to the creator. Technological innovations have made piracy easy and anyone can duplicate a motion picture on videotape a computer program, or a book. Video cassette recorders can be used by practically anyone to copy movies and television programs, and copying software has become almost as easy as copying a book. Large companies zealously monitor their copyrights for slogans, advertisements, and brand names, protected by a trademark 

What does the passage mainly discuss?