题目

已知函数，在中，， 且的面积为. （1）求角的值；  （2）求的值. 答案： 解：（1）= 由，得，得， ∵，∴     ∴       ∴           （2）由（1）知，又∵    ∴    ∴        由余弦定理得    ∴   ∴               由正弦定理得     ∴ 完形填空 阅读下面的短文，掌握其大意，然后从短文后各题所给的四个选项中，选择能填入相应空白处的最佳选项。 A Second Chance 　　Something in Stephen Pearman’s voice moved Robert Fredy one cold day two years ago．Pearman had come close to Fredy’s 　　1　　 at a crossroad in New York City, hoping to earn some money 　　2　　 washing his windshield(挡风玻璃)．Fredy waved to show he wasn’t interested． 　　Pearman leaned into the window．“Come on, mister, give me a chance．I need a 　　3　　,” he said． 　　In the seconds before traffic 　　4　　 moving again, Fredy, then general manager of the Berkeley-Carteret Hotel in Asbury Park, New Jersey, handed Pearman a business card and told him to call 　　5　　 he was serious． 　　“My friends told me he was just making a joke about me,” says Pearman, an out-of-work taxi and truck driver．“But I believed that he was a 　　6　　 businessman．” 　　The next day, 29-year-old Pearman appeared again 　　7　　 Fredy．Fredy gave him a job and three meals a day, and 　　8　　 him money while training him． 　　Today, Pearman works full time setting up the hotel’s meeting rooms．In the past two years, he’s found an apartment, married and paid back Fredy’s money． 　　“There’s no future in washing windshields,” says Pearman．“Mr．Fredy gave me a second chance, and I 　　9　　 the best use of it．” 　　Usually Fredy is very 　　10　　 with New York’s street people．“But pearman seemed so honest and open, 　　11　　 for an opportunity rather than just money,” Fredy says．“I don’t hand my business card to 　　12　　 anybody．But I’m glad I handed it to Pearman that day．” (1) [　　] A． house B． school C． company D． car (2) [　　] A． in B． by C． for D． with (3) [　　] A． help B． rest C． job D． money (4) [　　] A． tried B． kept C． stopped D． started (5) [　　] A． if B． as C． since D． because (6) [　　] A． kind B． rich C． happy D． strict (7) [　　] A． after B． before C． for D． to (8) [　　] A． got B． gave C． lent D． borrowed (9) [　　] A． did B． put C． made D． found (10) [　　] A． serious B． helpful C． friendly D． careful (11) [　　] A． working B． asking C． taking D． paying (12) [　　] A． just B． even C． only D． very