A、B两物体发生正碰,碰撞前后物体A、B都在同一直线上运动,其位移﹣时间图象(s﹣t图)如图中A、D、C和B、D、C所示.由图可知,物体A、B的质量之比为( )
A:1:1
B:1:2
C:1:3
D:3:1
14+34= ____
15×56= ____
710−710= ____
23×34= ____
①美元升值→资本流入→投资增加→刺激经济增长
②货币贬值→资本流出→加息减税→世界贸易和金融竞争加剧
③人民币贬值→资本流出→投资减少→经济下行压力增大
④减息减税→企业负担减轻→企业投资增加→国家债务风险减轻
下列单位换算正确的是()
(B) 根据句意和汉语注释,在答题卡标有题号的横线上,写出单词的正确形式。____ I have ordered several ________(册) of this book from abroad. Would you like to have one?____ The silk shirt feels much ___________ (光滑的) than the wool one.____ We are not sure if the man has any criminal ______________ (记录).____ Jim is so _______________ (幽默的) that he is always making us laugh.