【单选题】When the force disappears, the ship will _ _____its original shape due to ship’s hull flexibility.
【简答题】设a为第四象限的角,若 sin3a sina = 13 5 ,则tan2a=______.
【单选题】下列说法正确的是( )
A.
若 a ∥ b , b ∥ c ,则 a ∥ c
B.
若 cosα=- 4 5 ,sinα= 3 5 ,则2α的终边在第四象限
C.
若 a =(4,2) ,与 a 垂直的单位向量的坐标为 ( 5 5 ,- 2 5 5 )
【单选题】在平面直角坐标系内,若曲线C:x 2 +y 2 +2ax-4ay+5a 2 -4=0上所有的点均在第四象限内,则实数a的取值范围为( )
【单选题】低碳经济是指以低能耗、低污染、低排放为基础的经济模式,其实质是能源高效利用、开发清洁能源、追求绿色GDP,核心是能源技术创新、制度创新和人类生存发展观念的根本性转变。发展低碳经济,需要我们() ①加强自主创新,特别是科技创新 ②优化产业结构 ③坚决贯彻落实科学发展观 ④不断扩大企业生产规模
【简答题】The term ______ describes behavior of materials when subjected to some external force or condition.
【单选题】We expected that you () on here.
【单选题】According to the proposal, the multinational force will leave Iraq ______.
A.
when full sovereignty is restored to Iraq
B.
when the interim government takes power
C.
when the interim government asks them to leave