WHAT DOES “PLUS” IN “PASSWORD-PLUS” PROBABLY MEAN

42. What does “plus” in “password-plus” probably mean?A. Extra B. Long C. Fast D. DangerRead the following passage and mark the letter A, B, C, or D on your answer sheet toindicate the correct answer to each of the questions Scientists have discovered that for the last 160,000 years, at least, there has been aconsistent relationship between the amount of carbon dioxide in the air and the averagetemperature of the planet. The importance of carbon dioxide in regulating the Earth'stemperature was confirmed by scientists working in eastern Antarctica.Drilling down into a glacier, they extracted a mile-long cylinder of ice from the hole. Theglacier had formed as layer upon layer of snow accumulated year after year. Thus drillinginto the ice was tantamount to drilling back through time. The deepest sections of the core are composed of water that fell as snow 160,000 years ago.Scientists in Grenoble, France, fractured portions of the core and measured the compositionof ancient air released from bubbles in the ice. Instruments were used to measure the ratio ofcertain isotopes in the frozen water to get an idea of the prevailing atmospheric temperatureat the time when that particular bit of water became locked in the glacier. The result is a remarkable unbroken record of temperature and of atmospheric levels ofcarbon dioxide. Almost every time the chill of an ice age descended on the planet, carbondioxide levels dropped. When the global temperature dropped 9°F (5°C), carbon dioxidelevels dropped to 190 parts per million or so. Generally, as each ice age ended and the Earthbasked in a warm interglacial period, carbon dioxide levels were around 280 parts permillion. Through the 160,000 years of that ice record, the level of carbon dioxide in theatmosphere fluctuated between 190 and 280 parts per million, but never rose much higher-until the Industrial Revolution beginning in the eighteenth century and continuing today. There is indirect evidence that the link between carbon dioxide levels and globaltemperature change goes back much further than the glacial record. Carbon dioxide levelsmay have been much greater than the current concentration during the Carboniferous period,360 to 285 million years ago. The period was named for a profusion of plant life whoseburied remains produced a large fraction of the coal deposits that are being brought to thesurface and burned today.