按锅炉安装改造许可级别分类,可分为1、2两个级别。
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开挖挡墙基槽应从滑坡体两侧向中部分段跳槽进行,并加强支撑,及时砌筑和回填墙背,在作业时应设专人观察,严防塌方。
A. 正确
B. 错误
In some river mouths and estuaries the incoming high-tide wave crest overtakes the preceding low-tide trough. This results in a wall of water proceeding upstream,and is called a().
A. seiche
B. bore
C. boundary wave
D. surge
(埃纽斯)的史诗()摒弃了古老的神农格,并追溯了罗马的“既往”。