IELTS Reading: Multiple choice (Đáp án)

Đáp án bài Reading Multiple choice của tuần trước là B và C. Cơ sở để lựa chọn B và C là true statements như sau:

A) Edison’s electric light bulb was the most successful light bulb. Not Given

Statement A là Not Given vì trong bài đọc không có thông tin nào khẳng định như vậy.

B) Light bulbs invented by many previous inventors took too much money to produce, and therefore could not be sold widely. True

Many earlier inventors had previously devised incandescent lamps, including Alessandro Volta’s demonstration of a glowing wire in 1800 and inventions by Henry Woodward and Mathew Evans. Others who developed early and commercially impractical incandescent electric lamps included Humphry Davy, James Bowman Lindsay, Moses G. Farmer, William E. Sawyer, Joseph Swan and Heinrich Gobel. Some of these early bulbs had such flaws as an extremely short life, high expense to produce, and high electric currentdrawn, making them difficult to apply on a large scale commercially.

C) Edison failed to generate electric light using platinum and other kinds of metal. True

After many experiments, first with carbon filaments in the early 1880s and then with platinum and other metals, in the end Edison returned to a carbon filament. The first successful test was on October 22, 1879; it lasted 13.5 hours.

D) Edison and his colleagues received U.S patent for the invention of electric light bulb with carbonized bamboo filament. Not Given

Edison continued to improve this design and by November 4, 1879, filed for U.S. patent 223,898 (granted on January 27, 1880) for an electric lamp using “a carbon filament or strip coiled and connected to platina contact wires”

-> Đoạn này không có thông tin nào liên quan đến bamboo filament -> Not Given

E) Edison and some colleagues were looking for a material to produce a filament that can last for an extremely long time when they came to Battle Lake. False

The idea of using this particular raw material originated from Edison’s recalling his examination of a few threads from a bamboo fishing pole while relaxing on the shore of Battle Lake in the present-day state of Wyoming, where he and other members of a scientific team had traveled so that they could clearly observe a total eclipse of the sun on July 29, 1878, from the Continental Divide.

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