题目内容：
回答题：·Read the article below about highways in the United States．
·Choose the best word or phrase to fill each gap from A，B，C or D on the oppositepage．
·For each question(19-33)，mark one letter(A，B。C or D)on your Answer Sheet．
·There is arr example at the beginning(0)．
The United States is well-known for its network of major highways designed to help a driver get from one place to another in the shortest possible time．(19) ______these de modem roads are generally(20)______and weft maintained with(21) sharp CUn，es alld straight sect-ions，a direct route is not always the most(22) one．Large highways often pass(23)______ scenic areas and interesting small towns．Furtherrnore．these highways generally(24)______large urban centers，which means that they become crowded with(25)______traffic during rush hours，(26)the“fast，direct”route becomes a very slowroute．
However，there is almost always another route to take(27)______you are not in a hurryNot far from the(28)…．．．．new“superhighways”，there are often older(29)heavily traveled roads which go through the countryside． (30)______of these are good tw0—lane r。ads；others are uneven roads curving throut the c。untry．These secondary routes may go up steep slopes，along high(31)______，or down frightening hillside to towns(32)______in deep valleys．Through these less direct routes，longer and slower，they generaly go to places(33)______the air is clean and scenery is beautiful，and the driver may have a chance to get a flesh，clean view of the world．
19题答案为 A．Although
B．Since
C．Because
D．Therefore
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