Orchids are unique in having the most highly developed of all blossoms, in which the usual male and female reproductive organs are fused in a single structure called the column. The column is designed so that a single pollination will fertilize hundreds of thousands, and in some cases millions, of seeds, so microscopic and light they are easily carried by the breeze. Surrounding the column are three sepals and three petals, sometimes easily recognizable as such, often distorted into gorgeous, weird, but always functional shapes. The most noticeable of the petals is called the labellum, or lip. It is often dramatically marked as an unmistakable landing strip to attract the specific insect the orchid has chosen as its pollinator. To lure their pollinators from afar, orchids use appropriately intriguing shapes, colors, and scents. At least 50 different aromatic compounds have been analyzed in the orchid family, each blended to attract one, or at most a few, species of insects or birds. Some orchids even change their scents to interest different insects at different times.

   Once the right insect has been attracted, some orchids present all sorts of one-way obstacle courses to make sure it does not leave until pollen has been accurately placed or removed. By such ingenious adaptations to specific pollinators, orchids have avoided the hazards of rampant crossbreeding in the wild, assuring the survival of species as discrete identities. At the same time they have made themselves irresistible to collectors.

The word "fused" in line 2 is closest in meaning to .......

Câu hỏi liên quan

• What does the word "run" in the last paragraph mean?

• The word “they” in line 17 refers to ......

• What does the author probably mean by using the expression “children interrupt their education to go to school” (lines 2-3) ?

ZUNIA12

• The author’s tone in the passage is best described as .........

• The word "them" in the passage 2 refers to_________.

• The word "Here" in line 9 refers to……………

• The author uses the word “indeed” in the second paragraph for what purpose?

• Which of these statements is NOT TRUE?

• The word “they” in paragraph 5 refers to _______________.

• Sign language is said to be very picturesque and exact and can be used internationally EXCEPT for ..........

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

• The four boys of the Beatles ...............

• What is Martin Luthur King well- known for?

• The expression “on its own” in the last sentence can be best replaced by “.................”

• What does the word “it” refer to?

• What does the passage mainly discuss?

• In what year did Melville’s book about his experiences as a cabin boy appear?

• The phrase “academic responsibilities” in the second paragraph is closest in meaning to .............

• Which of the following is closest in meaning to “frigid” in paragraph 1?

• It can be inferred from the passage that, in summer, ________.