下列属于费力杠杆的是 （ ）
A．开瓶盖起子
B．道钉撬
C．筷子
D．钢丝钳
答案：C
阻力臂大于动力臂的杠杆属于费力杠杆，选C
The school ________I studied for only two years was three kilometers away.
A．what
B．that
C．where
D．which
运行下面的程序段： For k=5 to 10 Step 2 k=k*2 Next k 则循环次数为：______。
A．1
B．2
C．3
D．4
