根据我国《物权法》的规定，以企业债券进行质押的，质权设立的时间是( )。 A．主合

After delivering her second child, the client tells the nurse that she wants to breast-feed. She indicates that she was unsuccessful at breast-feeding her first child and that she bottle-fed after 3 days of trying to nurse. Which of the following responses would best support this client’s breast-feeding efforts（）

A. "I’ll make sure that you’re seen by the lactation consultant before you’re discharged. "

B. "It’s important to room-in with your neonate so that you can respond to her nursing: cues, "

C. "Don’t worry, every baby is different, and I’m sure that you’ll be successful this time. "

D. "Breast-feeding is possible but you must be committed to it. "

一根轻绳长1.6m，一端系在固定支架上，另一端悬挂一个质量为1kg的砂箱，砂箱处于静止。质量为10g的子弹以水平速度v₀＝50m/s打入砂箱，其后以v＝10m/s速度从砂箱穿出。g取10m/s²。求：

①砂箱获得速度后，上升的最大高度；

②砂箱从最高点返回到最低点处时，绳对砂箱的拉力大小。

将发束梳向预先设计的方向，与头皮成（）

A.直角

B.平角

C.锐角

D.钝角

E.45度

矿井的水大多来源于（）等。

A.地表水

B.大气降水

C.老窑积水

D.地下水