【判断题】In the U.S., assignments are felt to be given added weight by the passage of time.
【简答题】(3x﹣2y﹣5)(3x+2y﹣5)﹣2x(6x+y)﹣(3x﹣y)(﹣y﹣x)
【简答题】Given x,y,z∈R+ ,and 3x=4y=6z .Then write 3x, 4y, and 6z in order from least to greatest as ___.
【简答题】若x 2 ﹣y 2 =48,x+y=6,则3x﹣3y= _________ .
【单选题】简谐波y=50sin(3x+∏/6)的振幅是()
【简答题】已知(3x﹣y+2) 2 +|x+y+6|=0,则xy=( )。
【单选题】______ , he went to bed.
A.
A great weight taking off his mind
B.
With a great weight taking off his mind
C.
A great weight being taken off his mind
D.
With a great weight being taken off his mind
【简答题】已知实数x、y、z满足3 x =4 y =6 z >1. (1)求证: + = ; (2)试比较3x、4y、6z的大小.
【单选题】最近,医学家们通过用放射性 原子标记的 示踪发现, 的一种羧酸衍生物在特定条件下可通过断裂DNA杀死细胞,从而抑制艾滋病(AIDS)病毒。其中,关于放射性 的叙述中正确的是( )
【单选题】A variety o{ extracurricular activities are added in American schools______.
A.
to help students climb the education ladder
B.
to enrich students' dull life at school
C.
to help students become more successful in later life
D.
to extend college education down into elementary schools