Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following questions

Algae is a primitive form of life, a single-celled or simple multiple-celled 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?

• Câu 2: Mã câu hỏi: 44738

  Which of the following is NOT true about algae?

• Câu 3: Mã câu hỏi: 44739

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

• Câu 4: Mã câu hỏi: 44740

  Algae remnants found in Africa are________.

• Câu 5: Mã câu hỏi: 44741

  Green algae is generally found________.

  • A. on the ocean floor
  • B. on top of the water
  • C. throughout ponds and lakes
  • D. surrounding enclosed bodies of water

• Câu 6: Mã câu hỏi: 44742

  Brown algae would most likely be found________.

  • A. on trees
  • B. near green algae
  • C. on rocks
  • D. in the ocean

• Câu 7: Mã câu hỏi: 44743

  According to the passage, red algae is________.

  • A. sturdy
  • B. huge
  • C. fragile
  • D. found in shallow water

• Câu 8: Mã câu hỏi: 44744

  It can be inferred from the passage that limestone deposits serve as the basis of________.

  • A. coral reefs
  • B. red algae
  • C. subtropical seawater
  • D. secret passages