题目

（本题满分10分） 如图，当甲船位于处时获悉，在其正东方向相距20海里的处有一艘渔船遇险等待营救．甲船立即前往救援，同时把消息告知在甲船的南偏西30，相距10海里处的乙船. （Ⅰ）求处于处的乙船和遇险渔船间的距离； （Ⅱ）设乙船沿直线方向前往处救援，其方向与成角， 求的值域. 答案：（本题满分10分） 解：（Ⅰ）连接BC,由余弦定理得=202+102－2×20×10COS120°=700. ∴=10.        ………………4 （Ⅱ）∵，  ∴sin =………………6 ∵是锐角，∴………………7 =…………9 ∴的值域为.                      ……………………………………1034、In the West，there can be some abbreviations（缩略词）in some advertisements（广告）of the newspaper．Here's an advertisement for an apartment（公寓套房）．Most of the words in it are abbreviations，for example，Lrg．apt，i．e．（即）Large apartment；Lrg．lvrm，i．e．Large living-room．Now，please read the advertisement carefully，and then fill in each blank with ONE word． For Rent Lrg．apt    Fourth flr．   Very quiet bldg． No pets．   Two bedrms．   Lrg．lvrm． Ut1．pd．   Unfrn．        Gd．1ctn． ＄220 per mo．             Call 662—3940 Complete the following sentences according to the passage above． 1．The apartment is on the _________ floor of the building． 2．If you rent（租用）the apartment，do（千万）remember not to bring（带来）any _________ ，like dogs，cats，birds and so on． 3．There is a large living-room and two _________ in the apartment． 4．The location（位置）of the building is very _________ ． 5．If you rent the apartment，you must pay（付）_________ dollars（美元）every month．