Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 30 to 37. Humans have struggled against weeds since the beginnings of agriculture. Marring our gardens is one of the milder effects of weeds – any plants that thrive where they are unwanted. They clog waterways, destroy wildlife habitats, and impede farming. Their spread eliminates grazing areas and accounts for one-third of all crop loss. They compete ...
Tô Hương Liên | Chat Online | |
02/09 12:18:07 (Tiếng Anh - Lớp 12) |
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 30 to 37.
Humans have struggled against weeds since the beginnings of agriculture. Marring our gardens is one of the milder effects of weeds – any plants that thrive where they are unwanted. They clog waterways, destroy wildlife habitats, and impede farming. Their spread eliminates grazing areas and accounts for one-third of all crop loss. They compete for sunlight, nutrients, and water with useful plants.
The global need for weed control had been answered mainly by the chemical industry. Its herbicides are effective and sometimes necessary, but some pose serious problems, particularly if misused. Toxic compounds threaten animal and public health when they accumulate in food plants, groundwater, and drinking water. They also harm workers who apply them.
In recent years, the chemical industry has introduced several herbicides that are more ecologically sound. Yet new chemicals alone cannot solve the world’s weed problems. Hence, scientists are exploring the innate weed-killing powers of living organisms, primarily insects and microorganisms.
The biological agents now in use are environmentally benign and are harmless to humans. They can be chosen for their ability to attack selected targets and leave crops and other plants untouched. In contrast, some of the most effective chemicals kill virtually all the plants they come in contact with, sparing only those that are naturally resistant or have been genetically modified for resistance. Furthermore, a number of biological agents can be administered only once, after which no added applications are needed. Chemicals typically must be used several times per growing season.
The word ‘marring’ in bold is closest in meaning to ........
Lựa chọn một trả lời để xem Đáp án chính xác Báo sai đáp án hoặc câu hỏi |
A. planting 0 % | 0 phiếu |
B. spoiling 0 % | 0 phiếu |
C. dividing 0 % | 0 phiếu |
D. replacing 0 % | 0 phiếu |
Tổng cộng: | 0 trả lời |
Trắc nghiệm liên quan
- Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 25 to 29. A trend that has emerged recently is the sharing of childcare (25) ... (Tiếng Anh - Lớp 12)
- Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 25 to 29. A trend that has emerged recently is the sharing of childcare (25) ... (Tiếng Anh - Lớp 12)
- Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 25 to 29. A trend that has emerged recently is the sharing of childcare (25) ... (Tiếng Anh - Lớp 12)
- Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 25 to 29. A trend that has emerged recently is the sharing of childcare (25) ... (Tiếng Anh - Lớp 12)
- Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 25 to 29. A trend that has emerged recently is the sharing of childcare (25) ... (Tiếng Anh - Lớp 12)
- By the end of 2010 we_______ in Ho Chi Minh City for 30 years. (Tiếng Anh - Lớp 12)
- Williams is working _______ an export company. He intends to apply _______ another job because he is not satisfied _______ the salary. (Tiếng Anh - Lớp 12)
- He advised them _________ in the class. (Tiếng Anh - Lớp 12)
- Her job was so _________ that she decided to quit it. (Tiếng Anh - Lớp 12)
- Mr. Thompson is learning Vietnamese _________ to read Kim Van Kieu. (Tiếng Anh - Lớp 12)
Trắc nghiệm mới nhất
- Calcium hydroxide là chất rắn màu trắng, ít tan trong nước. Phát biểu nào sau đây sai? (Khoa học tự nhiên - Lớp 9)
- Ứng dụng của silicon là (Khoa học tự nhiên - Lớp 9)
- Từ cát thạch anh (cát trắng) sản xuất ra (Khoa học tự nhiên - Lớp 9)
- Công đoạn chính để sản xuất đồ gốm theo thứ tự lần lượt là (Khoa học tự nhiên - Lớp 9)
- Phát biểu nào sau đây không đúng về silicon? (Khoa học tự nhiên - Lớp 9)
- Vì sao vôi tôi được sử dụng để xử lí SO2 trong khí thải? (Khoa học tự nhiên - Lớp 9)
- Nhỏ một vài giọt hydrochloric acid lên một viên đá vôi thu được hiện tượng nào sau đây? (Khoa học tự nhiên - Lớp 9)
- Để sản xuất thủy tinh loại thông thường, cần các nguyên liệu nào sau? (Khoa học tự nhiên - Lớp 9)
- Vôi tôi là tên gọi của hợp chất nào sau đây? (Khoa học tự nhiên - Lớp 9)
- Quặng nào sau đây không có thành phần chủ yếu là oxide của kim loại? (Khoa học tự nhiên - Lớp 9)