【单选题】下列对人地关系的叙述,正确的是( )
D.
只要充分发挥人的主观能动作用,环境就可以按照人类的意志发展
【单选题】In the metals industry, hydrogen is used to prevent metals from tarnishing while undergoing______.
【单选题】According to the author, in what way are the metals and people alike?
B.
They both suffer from stress.
C.
They are easy to snap.
D.
They will snap when the level of stress is over a point.
【简答题】已知椭圆C焦点在x轴上,其长轴长为4,离心率为 3 2 , (1)设过定点M(0,2)的直线l与椭圆C交于不同的两点A、B,且∠AOB为锐角(其中O为坐标原点),求直线l的斜率k的取值范围; (2)如图,过原点O任意作两条互相垂直的直线与椭圆 x 2 a 2 + y 2 b 2 =1 (a>b>0)相交于P,S,R,Q四点,设原点O到四边形PQSR一边的距离为d,试求d=1时a,b满足的条件.
【判断题】In impact testing of metals, metals will experience ductile failures with much greater absorption of energy below the critical temperature.
【单选题】People and metals all have a point at which they will be overcome by the pressure being _______.
【单选题】下述C语言代码的运行结果是( )。 static void Main(string[] args) { int a=2,b= -1,c=2; if(a
【单选题】下述C#语言代码的运行结果是( )。
C.
num1大 num1=50 num2大 num2=30
【单选题】下列对人地关系的叙述,正确的是( )
D.
只要充分发挥人的主观能动作用,环境就可以按照人类的意志发展