为什么不允许代替套管服务人员操作套管卡盘?
参考答案:
操作不熟练,配合不默契,可能发生操作失误,导致人员伤亡。
根据A句完成B句,使其意思相同或相近,每空填写一词。
1. A: What do you think of the movie Avatar (《阿凡达》)?
B: _______ do you _______ the movie Avatar?
2. A: He liked chocolate, and he liked biscuits, too.
B: he liked _______ chocolate _______ biscuits.
3. A: I hope I can forget all my problems.
B: I hope _______ _______ all my problems.
4. A: I will fail the exam without your help.
B: If you _______ help me, I won't _______ the exam.
5. A: In her eyes, the cute dog is her best friend.
B: She _______ the cute dog _______ her best friend.
下列描述的元素一定属于金属元素的是( )
A.易失去电子的物质所含元素
B.易与酸反应的物质所含元素
C.原子核内有13个质子的元素
D.原子的最外电子层只有1个电子的元素