（新课标）2018年高三英语一轮复习 题组层级快练34 Unit 4 Sharing 新人教版选修7.docVIP

题组层级快练34 Unit 4 Sharing 阅读速度提升练(时间：20分钟)Ⅰ.阅读理解阅读下列短文从每题所给的四个选项(A、B、C和D)中选出最佳选项。 (改编)The brown widow spider became established in Southern California in early 2000 and has become part of the local spider family in urban Los Angeles and San Diego. The brown widow spider is continuing its expansion in Southern California and could possibly move northward into Central California. The brown widow is suspected to have evolved in Africa although it was first described from South America, which adds confusion as to where it might have originated. It is a tropical and subtropical spider having established populations in Hawaii, Florida, parts of Australia, South Africa and Japan. In North America, the brown widow was restricted for many decades to the Florida peninsula. However, around the year 2000, it started showing up in other Gulf Coast states. Brown widows are now known from Texas to Georgia and South Carolina. The brown widow builds its web in protected sites around homes and in woody vegetation with branches. Some typical sites selected by brown widows for web building are empty containers such as buckets and nursery pots, mail boxes, entry way corners, under eaves, storage closets and garages, undercarriages of motor vehicles that are stationary for long periods, and the undersides of outdoor furniture. They choose places that are more exposed than sites chosen by black widows and therefore, appear to be at higher risk for interactions with humans as far as bites are concerned. One recent study demonstrates that the brown widow spider is less poisonous than other widow species. The reason for the weaker effect of brown widow bites on humans is possibly because the brown widow does not have much poison as its larger relatives, but it is really a threat to humans as to its poison. The two major symptoms of a brown widow bite were that the bite hurt when it was given and it left a red mark. These two symptoms are not much different from the bite of normal household sp