Aconspicuoussign indicating the presence of white-tailed deer in a woodlot is abuckrub.

Amaledeer makes abuckrubby striping thebark(outerlayer) of a small tree with its antlers. When completed, thebuckrubis anobviousvisualsignalto us and presumable to other deer in the area. Arubis usually located at the shoulder height of a deer

(one meter or less above the ground) on a smooth-barked, small-diameter (16-25 millimeters) tree. The smoothbarkof small red maples makes thisspeciesidealforbuckrubs in the forests of

the mid-eastern United States.

Adultmaledeer usually produce rubs in late summer or early autumn when the outer velvetlayeris beingshedfrom their antlers. Rubs are created about one to two months before thebreedingseason(the rut). Hence for a long time biologists believed thatmaledeer usedbuckrubs not only to clean andpolishantlers but also to provide practice for the ensuing male-to-malecombatduring the rut. However, biologists alsonoteddeer sniff and lick an unfamiliarrub, which suggests that thisvisualmark on a small tree plays an important communication purpose in the social life of deer.

Buckrubs also have ascentproduced by glands in the foreheads of deer that is transferred to the tree when therubis made. These odors makebuckrubs an important means ofolfactorycommunication between deer. The importance ofolfactorycommunication (using odors tocommunicate) in the way of life of deer was documented by a study ofcaptiveadultmaledeer a few decades ago, whichnotedthat males rubbed their foreheads on branches and twigs, especially as autumn approached. Adecadelater another study reported that adultmalewhite-tailed deer exhibited forehead rubbing just before and during the rut. It was found that when a white-tailedbuckmakes arub, it moves both antlers and forehead glandsalongthe small tree in averticaldirection. This forehead rubbingbehaviorcoincides with a highlevelof glandularactivityin the modifiedscentglands found on the foreheads ofmaledeer; the glandularactivitycauses the forehead pelage (hairy covering) of adult males to be distinctly darker than in females or younger males.

Forehead rubbing bymaledeer onbuckrubspresumablysends a greatdealof information to other members of the samespecies. First, the chemicals deposited on therubprovide information on theindividualidentityof an animal; no two mammals produce the samescent. Forinstance, as we all know, dogsrecognizeeach other via smell. Second, because onlymaledeerrub, thebuckruband its associated chemicalsindicatethe sex of the deer producing therub. Third, older, moredominantbucks produce morebuckrubs and probablydepositmore glandular secretions on agivenrub. Thus the presence of many well-marked rubs isindicativeof older, higher-status males being in the generalvicinityrather thansimplybeing acrudemeasureofrelativedeerabundancein agivenarea. The information conveyed by theolfactorysignals on abuckrubmake it the socialequivalentof someauditorysignals in other deerspecies, such as trumpeting by bull elk.

Because both sexes of white-tailedrespondtobuckrubs by smelling and licking them, rubs may serve a very importantadditionalfunction. Fresherbuckrubs (less than two days old), inparticular, are visited more frequently by adult females than older rubs. In view of thisbehaviorit has been suggested that chemicals present in freshbuckrubs may helpphysiologicallyinduceandsynchronizefertilityin females that visit these rubs. This would be anobviousadvantageto wide-ranging deer, especially to a sociallydominantbuckwhen courting several adult females during the autumn rut. Anothervisualsignalproduced by while-tailed deer is termed abuckscrape. Scrapesconsistof a clearing (about 0.5 meter indiameter) andshallowdepressionmade by pushing aside the leaves covering the ground; after making thescrape, the deer typically urinates in thedepression. Thus, like abuckrub, ascrapeis both avisualand anolfactorysignal. Buckscrapes are generally created after leaf-fall in autumn, which is just before or during the rut. Scrapes are usually placed in open orconspicuousplaces, such asalonga deertrail. Most are made by older males, although females and younger males (2.5 years old or less) occasionally make scrapes.

Questions:
question_stem: The word “conspicuous”in the passage is closest in meaning to
choices: tag: A
text: noticeable

tag: B
text: common

tag: C
text: strange

tag: D
text: particular
answer_key: A
explanation: A conspicuous: 显著的，显而易见的。和 A 选项的 noticeable 对应。对应原文 A conspicuous sign indicating the presence of white-tailed deer in woodlot is a buck rub.这里说一个 XX 的标志可以说明白尾鹿的存在。再往后,第三句有一个同意的句子，说" the buck rub is an obvious visual signal to us..." 由此可得出 conspicuous 是 obvious 的同义词。因此选 A 选项的 noticeable（引人注意的）。BCD 分别是常见的;奇怪的;特别的。

question_stem: According to paragraph 1, why are small red maple trees ideal for buck rubs?
choices: tag: A
text: They have smooth bark.

tag: B
text: They are found in the mid-eastern United States.

tag: C
text: They grow very slowly.

tag: D
text: They tend to grow in open spaces.
answer_key: A
explanation: A 根据 small red maple tree 定位到该段最后一句话： The smooth bark of small red maples makes this species ideal for buck rubs in the forests of the mid-eastern United States.这句话的主语其实是"The smooth bark"，因此知道 they have smooth bark 才是成为理想对象的重要条件。