老托福阅读真题及答案:passage11 为了帮助大家备考托福阅读，提高成绩，下面我给大家带来老托福阅读真题及答案:passage 11，希望大家喜欢！ 老托福阅读真题及答案:passage 11 Planever, are triggered in reaction to intrusion, implying that the host has some means of recognizing the presence of a foreign organism. The most dramatic example of an inducible plant defense reaction is the hypersensitive response. In the hypersensitive response, cells undergo rapid necrosis — that is, they become diseased and die — after being penetrated by a parasite; the parasite itself subsequently ceases to grow and is therefore restricted to one or a few cells around the entry site. Several theories have been put forward to explain the basis of hypersensitive resistance.
1. What does the passage mainly discuss? (A) The success of parasites in resisting plant defense mechanisms (B) Theories on active plant defense mechanisms (C) How plant defense mechanisms function (D) How the immune system of animals and the defense mechanisms of plants differ 2. The phrase subject to in line 1 is closest in meaning to (A) susceptible to (B) classified by (C) attractive to (D) strengthened by 3. The word puncture in line 8 is closest in meaning to (A) pierce (B) pinch
(C) surround (D) cover . 4. The word which in line 12 refers to (A) tissues (B) substances (C) barriers (D) insects 5. Which of the following substances does the author mention as NOT necessarily being toxic to the Colorado beetle? (A) resins (B) tannins (C) glycosides (D) alkaloids 6. Why does the author mention glycoproteins in line 17? (A) to compare plant defense mechanisms to the immune system of animals (B) to introduce the discussion of active defense mechanisms in plants (C) to il
