IV: Read the following passage and mark the letter A, B, C, or Don your answer sheet to tướng indicate the correct answer for each of the question:
Water scarcity is fast becoming one of the major limiting factors in world crop production. In many areas, poor agricultural practices have led to tướng increasing desertification and the loss of formerly irable lands. Consequently, those plant species that are well adapted to tướng survival in dry climates are being looked at for an answer in developing more efficient crop to tướng grow on marginally arable lands.
Plants use several mechanisms to tướng ensure their survival in desert environments. Some involve purely mechanical and physical adaptation, such as the shape of the plant's surface, smaller leaf size, and extensive root systems. Some of the adaptations are related to tướng chemical mechanisms. Many plants, such as cacti, have internal gums and mucilages which give them water-retaining properties. Another chemical mechanism is that of the epicuticular wax layer. This wax layer acts as an impervious cover to tướng protect the plant. It prevents excessive loss of internal mixture. It also protects the plant from external aggression, which can come from inorganic agents such as gases, or organic agents which include bacteria ant plant pests.
Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed, such a compound could be used to tướng greatly increase a planes ability to tướng maintain health in such adverse situations as inadequate water supply, limited fertilizer availability, attack by pests, and poor storage after harvesting.
This passage đơn hàng mainly with…………………
A. desertification
B. decreasing water supplies
C. factors limiting crop production
D. developing efficient plants
Đáp án D
Consequently, those plant species that are well adapted to tướng survival in dry climates are being looked at for an answer in developing more efficient crops to tướng grow on marginally arable lands.
The word “arable” in the first paragraph is closest in meaning to………………
A. fertile
B. parched
C. barren
D. marsh
Đáp án A
Arable = fertile : màu sắc mỡ
Which of the following is a mechanical or physical mechanism that desert plants use?
A. The plant’s shape
B. The small root system
C. The vast leaf size
D. The high water consumption
Đáp án A
Plants use several mechanisms to tướng ensure their survival in desert environments. Some involve purely mechanical and physical adaptations, such as the shape of the plant’s surface,…
The word “extensive” in the second paragraph is closest in meaning to tướng …………….
A. spongy
B. snallow
C. widespread
D. comprehensive
Đáp án C
Extensive = widespread : không ngừng mở rộng, mở rộng.
Which is one of the way in which the epicuticular wax protects the plant?
A. It helps the plant to tướng avoid excessive moisture intake
B. It helps the plant to tướng attack aggressors
C. It releases gases against plant pests
D. It guards against bacteria
Đáp án D
This wax layer acts as an impervious cover to tướng protect the plant. It also protects the plant from external aggression, … or organic agents which include bacteria ant plant pests.
The word "It" in the second paragraph refers to--------
A. another chemical mechanism
B. the epicuticular wax layer
C. an impervious plantlike cover
D. the loss of internal moisture
Đáp án B
“It” = “the epicuticular wax layer”
The word “aggression” in the second paragraph is closest in meaning to………….
A. attack
B. agitation
C. conditions
D. surroundings
Đáp án A
“Aggression = attack” : sự tiến công.
What is an example of an inorganic agent that may attack plants?
A. Bacteria
B. Insects
C. Gas
D. Pests
Đáp án C
“…inorganic agents such as gases…”
It can be inferred that synthetic simulated waxes.........................
A. have not been developed yet
B. have not succeeded
C. have been determined to tướng be impervious to tướng organic and inorganic agents
D. have the quality of causing bacteria
Đáp án A
“Researchers have proposed that synthetic waxes with similar protective abilities could be prepared based on knowledge of desert plants. If successfully developed…”
All of the following are examples of an adverse situation for crops EXCEPT……
A. inadequate water
B. insufficient fertilize
C. pest aggression
D. proper storage
Đáp án D
“… in such adverse situations as inadequate water supply, limited fertilizer availability, attack by pests, and poor storage after harvesting.” “Adverse situation” : ĐK bất lợi; “proper storage” : bảo vệ tốt><”poor storage”