dropping into短语⁶³¹⁷² 基本例句 不知不觉变得；顺便进入；偶然进入 When the installation of the equipment done, cover with plank the connecting holes and flanges so as to prevent tools, hard articles or welding dregs from dropping into the bucket. 设备安装时，应把接孔和法兰处，用木板盖好，以防工具、硬物和电焊溶渣落入设备内，损坏设备。 jiangnantangci