水泥腐蚀的类型有哪些？

叶圣陶先生说过：“心里知道该怎么做，未必就能养成好习惯；必须怎样怎样去做，才可以养成好习惯。”这句话强调了（  ）

①培养好习惯必须要有计划和决心

②培养好习惯必须要有实际行动

③培养好习惯必须改掉坏习惯

④培养好习惯必须把培养好习惯的想法落实到行动中去

A．②④

B．①②③

C．②③④

D．①③

Six men have been trapped in a mine for seventeen hours. If they are not brought to the surface soon they may lose their_____小题1:____ (life). However, rescue operations are _____小题2:____ (prove) difficult. If explosives are used, vibrations will cause the roof of the mine ____小题3:_____ (collapse). Rescue workers are therefore drilling a hole on the north side of the mine. They intend to bring the men up in    小题4:   special capsule.     小题5:    there had not been a hard layer of rock beneath the soil, they would have completed the job in a few hours. As it is, they have been drilling for sixteen hours and they still have a long way to go. Meanwhile, a microphone, which   小题6:  (low) into the mine two hours ago, has enabled the men to keep in touch with the closest relatives. Though they are running out of food    小题7:     drink, the men are     小题8:  (cheer) and confident that they will get out soon. They have been told that rescue operations are progressing     小题9:   (smooth). If they knew how difficult it was to drill      小题10:   the hard rock, they would lose heart.

事故简要经过：某日晚上，一码头内，起重机操作人员在抓吊石子作业时，工人罗某从船中走来，操作人员未知其进入，抓斗撞击到罗某背部，送医院抢救无效死亡。事故调查：该抓斗定检合格，在有效期内使用，检查没有发现存在与事故相关的设备缺陷。操作人员持证上岗，未发现有违章操作行为。事故原因分析（）

A.缺少现场的安全管理

B.设备有缺陷

C.没有配足作业现场的灯光

D.安全装置失灵

各级行应根据“传世之宝”的（）等条件分别在实物黄金系统中开户表外账户。

A.品种

B.规格

C.破损标记

D.正常

实战中使用撤步，其作用躲闪对方的进攻。