问题
单项选择题
His complaint about our management was not without reasons.
A. could be rectified
B. could be justified
C. was modified
D. could be enforced
答案
参考答案：B
解析：can be justified等同于not without reasons的说法。
进入水平轨道瞬间速度为
，此时金属杆
处在静止状态，