三相四线制线路支上装用的漏电保护器应当采用（）极式漏电保护器。
A.2
B.3
C.4
参考答案：A
_________ by the beautiful scenery of the west Lake, the foreigners decided to spend another two days in Hangzhou.
A．Attracting
B．Attracted
C．To be attracted
D．Having Attracted.
以下符合PVC外周静脉留置针穿刺步骤的有（）
A.取舒适体位，解释说明穿刺目的及注意事项
B.选择静脉
C.皮肤消毒
D.扎止血带，绷皮进针
E.选择合适的敷料固定
