­Until the Apollo astronauts brought samples of lunar material to Eart

‎ ‎ ‎ ‎ ‎ ­Until the Apollo astronauts brought samples of lunar material to Earth during 1969-72, scientists believed that the Moon's surface was largely undisturbed, given its dry, airless environment. Examination of the samples has shown otherwise. Micrometeorites, many smaller than a pencil point, constantly rain onto the Moon at up to 100,000 kilometers per hour, chipping materials or forming microscopic craters. Some melt the soil and vaporize and recondense as glassy coats on other specks of dust. Impacts weld debris into lumps of heterogeneous matter called "agglutinates." Complicated interactions with solar particle streams convert iron into myriads of microscopic iron grains. The regolith-pebbles, sand, and dust- from these erosion processes  blankets the Moon. Much of the top layer consists of a complex abrasive dust of microscopic glass shards that can grind machinery and sealing devices and damage human lungs.

 ‎ ‎ ‎ ‎ ­The Apollo specimens held by the United States are doled out in ultra-small samples to scientists who demonstrate that nothing else will suffice for high-value experiments. Renewed interest in lunar exploration in the late 1980s meant that materials designed to simulate lunar regolith-simulants -were needed for research to develop schemes for lunar building and procedures for extracting elements such as oxygen found abundantly in regolith. That led to the development of JSC-1 in 1993, made of volcanic cinder cone from a quarry in Arizona in the U.S. The more than 22 metric tons made was in high demand. Efforts are now afoot to manufacture 16 metric tons of JSC-1A, with 1 ton of fine grains, 14 tons of moderately fine, and 1 ton of coarse.

 ‎ ‎ ‎ ‎ ­Currently, three new simulants are being developed. Two will represent the Moon's dry seas region and polar highlands region. A third will represent the glassy, jagged edges of lunar dust that test the best of hardware and humans. But since matching every lunar location would require large numbers of small, unique, expensive batches, the intention is to develop a few "root simulants," blends of which will yield regionally specific simulants. For example, ilmenite, a crystalline iron-titanium oxide, is a crucial ingredient for the new dry seas region simulant. Raw materials for the three new stimulants will come from sites in the U.S. and even some international sites­

1. The information in the passage most strongly supports which of the following claims about the samples of lunar material brought back from the Moon by the Apollo astronauts?

A. Scientists for whose experiments JSC-1A would suffice are not regarded as entitled to obtain material from the samples.
B. Only scientists working on the development of simulants of lunar regolith have access to the samples.
C. The samples were of all the major types of lunar regolith.
D. The samples' ingredients included some cinder cone from lunar volcanoes.
E. Only one of the samples contained ilmenite.



2. It can be most reasonably inferred from the passage that if robots were used instead of humans to explore the Moon, then

A. lunar soil could be analyzed without returning it to Earth
B. lunar exploration would be no less expensive than lunar exploration by humans
C. simulants of lunar regolith would not be needed in order to prepare for the lunar missions
D. those robots would function well only if they were engineered to resist certain characteristics of lunar regolith
E. solar particle streams would not pose less of a problem for robotic exploration than they pose for human exploration


3. Which of the following most accurately describes the primary purpose of the passage?

A. To set out in detail a scientific hypothesis and provide evidence for it
B. To report and set in context a research and development program
C. To explore the major challenges confronting an innovative project
D. To propose a solution to a major problem encountered by a scientific program
E. To show how a long accepted scientific viewpoint has changed


4. According to the passage, which of the following statements about lunar regolith simulants is true?

A. Each of them contains an ingredient unique to it.
B. Not all the raw materials for them are to be obtained from mines and quarries located in the United States.
C. Most of them contain very small amounts of materials brought back from the Moon.
D. They are not in every case designed to have approximately the same chemical composition as lunar regolith itself.
E. The main ingredient for most of them is volcanic cinder cone.­