Câu hỏi:
30/03/2020 445Read 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.
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.
With what topic does this passage primarily deal?
Đáp án chính xác
Câu hỏi trong đề:
KỲ THI THỬ THPT QUỐC GIA NĂM 2019 MÔN TIẾNG ANH !!
Sách mới 2k7: Tổng ôn Toán, Lí, Hóa, Văn, Sử, Địa…. kỳ thi tốt nghiệp THPT Quốc gia 2025, đánh giá năng lực (chỉ từ 110k).
Quảng cáo
Trả lời:
Giải bởi Vietjack
Đáp án : D
THông tin:
- In recent years, the chemical industry has introduced several herbicides that are more ecologically sound.
- The biological agents now in use are environmentally benign and are harmless to humans
Bài viết nói lên tác dụng của tác nhân sinh học vượt trội hơn hẳn tác nhân hoá học
Nhà sách VIETJACK:
CÂU HỎI HOT CÙNG CHỦ ĐỀ
Câu 2:
Mark the letter A, B, C or D on your answer sheet to show the underlined part that needs correction in each of the following questions.
Animals and man (A) use the energy finding (B) in food to operate (C) their body and (D) muscles.
Xem đáp án »
30/03/2020
20,842
Câu 3:
The weather is going to change soon; I feel it in my _________ .
Xem đáp án »
30/03/2020
20,085
Câu 4:
Mark the letter A, B, C or D on your answer sheet to show the underlined part that needs correction in each of the following questions.
Not until much (A) later did she realize (B) that her long-known (C) partner had been lying her. (D)
Xem đáp án »
30/03/2020
18,581
về câu hỏi!