show+sb+off
艾唯东3748It's+形容词+for sb+动词不定式,是什么语法结构??? -
翁健典18382974852 ______ it是形容词主语,动词不定式是真正的主语,故也可写成:动词不定式 +BE +形容词+for sb . 如It 's important for us to learn English well .= To learn English well is very important for us .
艾唯东3748lt is+形容词+for sb或to sb+动词不定式什么情况下用for什么情况下用to? -
翁健典18382974852 ______[答案] 1、动词不定式作主语是被动语态时用 to sb 例如:It's a great honour to Mary's birthday partyto be invited. 2、动词不定式作主语是主动语态时用 for sb 例如:It was impossible for lost time to be made up.
艾唯东3748(2003•绵阳)如果一个三角形的三边的长分别为a、b、c,那么可以根据秦九韶 - 海伦公式S=(其中p=(a+b+c))或其它方法求出这个三角形的面积.试求出三... -
翁健典18382974852 ______[答案] 直接根据公式把三边长分别为分别代入S=即可求解. 【解析】 ∵三边长分别为, ∴p=(a+b+c)=(+3+2)= ∴S2=***=9 ∴S=3.
艾唯东3748按要求用It's+adj, +of sb.,+to do sth句型完成句子 -
翁健典18382974852 ______ 1.David doesn't forget to do the things he needs to do.------- It is good / dutiful of David not to forget to do the things he needs to do.2.He doesn't show off in front of his classmates.---------It is modest / good / low-profiled of him not to show off in front of his classmates.
艾唯东3748用一下句式翻译 It is +名词+for sb+to do ath 我受邀到这儿来做关于如何组用一下句式翻译It is +名词+for sb+to do ath我受邀到这儿来做关于如何组织全球环境... -
翁健典18382974852 ______[答案] 我受邀到这儿来做关于如何阻止全球环境恶化的演讲非常荣幸 It is a pleasure for me to be invited here to make the speech on how to prevent the global environment from deteriorating .
艾唯东3748a=3.5,b=5.4,c=4.3,编程三角形的面积,Area=√s*(s - a)*(s - b)*(s - c),其中s=(a+b+c)/2 -
翁健典18382974852 ______ #include#include#define s (a+b+c)/2#define Area sqrt(s*(s-a)*(s-b)*(s-c)) void main() { float a,b,c; scanf(＂%f%f%f＂,&a,&b,&c); printf(＂%5.2f＂,Area); }
艾唯东3748设绝对值小于1的全体实数的集合为S,在S中定义一种运算*,使得a*b=(a+b)/(1+ab),求证:如果a与b属于S,那么a*b也属于S -
翁健典18382974852 ______[答案] 依题意,S={x|-1如果a与b∈S,那么-1要证a*b∈S,就是要证明-1(a*b+1)(a*b-1) =[ (a+b)/(1+ab)+1] [ (a+b)/(1+ab)-1] =[a+b-1-ab] [a+b+1+ab]/(1+ab)² =[(a-1)(1-b)] [(a+1)( b+1)] /(1+ab)² 因为-10,a+1>0,b+1>0,所以上式小于0,故原命题得证
艾唯东3748已知三角形的三边为a、b、c,设p=1/2(a+b+c),求证三角形的面积S=√p(p - a)(p - b)(p - c) -
翁健典18382974852 ______[答案] 证明:若ΔABC的三边长为a、b、c,则SΔABC=√((a+b+c)*(-a+b+c)*(a-b+c)*(a+b-c))/4(这是海伦公式的变形,“负号“-”从a左则向右经过a、b、c”,负号从x轴负轴向正轴扫描一个周期!我觉得这么...