进行电阻点焊时，第一个焊点和第二个焊点的电流调节相比（）
A.第一个大，第二个小
B.第一个小，第二个大
C.可以同样大
参考答案：B
一个平行四边形的面积是24平方米，高缩小3倍，底不变，面积是（ ）平方米。
Kate had a terrible time this summer. Not a day ________ without having some unpleasantness with her sister at home.
A．she spent
B．she had spent
C．did she spend
D．had she spent
