(A) 200
(B) 2,000
(C) 20,000
(D) 200,000
5.Which of the following is a kind of petal?
(A) The column
(B) The sepal
(C) The stem
(D) The labellum
6.The labellum(line10) is most comparable to
(A) a microscope
(B) an obstacle course
(C) an airport runway
(D) a racetrack
7.The word "lure" in line 13 is closet in meaning to
(A) attract
(B) recognize
(C) follow
(D) help
8.Which of following is NOT mentioned as a means by which an orchid attracts insects?
(A) Size
(B) Shape
(C) Color
(D) Perfume
9.The word "their" in line 17 refers to
(A) orchids
(B) birds
(C) insects
(D) species
10.Which of the following statements about orchids’ scents does the passage support?
(A) They are effective only when an insect is near the blossom.
(B) Harmful insects are repelled by them.
(C) They are difficult to tell apart.
(D) They may change at different times.
11.The word "placed" in line 21 is closet in meaning to