China has recently ______ its waters controls near the Diaoyu Islands to prevent Chinese fishing boats from ______ in the East China Sea．

A．show up; attacking

B．taken up; having attacked

C．stepped up; being attacked

D．picked up; having been attacked

在测量故障曲线时，弦线两端及量尺均应在外轨内侧的轨顶下（）。

A、13mm；

B、14mm；

C、15mm