怎样保证预塔的萃取效果长周期运行？

一个圆锥体的底面半径是6厘米，高是1分米，体积是______立方厘米．

“How can I learn English well?” This is a question many students ask. In my opinion, the most effective way is to learn lessons by heart. If you can recite(背诵) the text and write it out, you’ve learned it fairly well. And if you can tell, in your own words, what the lesson says, you’re a very successful learner indeed. Your English will be quite perfect.

This is a difficult task. However, if you try to learn by heart only part of each lesson, you’ll find it not half so hard as you might have thought. Learning this way, you will make rapid progress. Of course, writing is also necessary. It helps you a lot on our way to success in English.

Equally important is to feel the language. You should be able to laugh at jokes and be shocked at bad news. When using English, try to forget your mother tongue. Instead of helping you, your own language gets in your way. So, never try to see English through translation.

小题1:In the writer’s opinion, the most effective way in learning English is _______.

A．to practise speaking, writing and feeling it

B．to memorize the English words and grammatical rules

C．to translate everything into his own language

D．to forget your own native language小题2:“Instead of helping you, your own language gets in your way.”This sentence means that memorizing your own language can ________.

A．stop you mastering English

B．help you study English well

C．make English easy to learn

D．help you notice mistakes小题3:The underlined words“to feel the language” here means________.

A．to get a knowledge of English by touching

B．to be able to read and write English

C．to be able to experience the rich feeling of the language

D．to translate English into your own by imagining

根据《建设工程安全生产管理条例》的规定，甲是分包单位从事高空作业的作业人员，则（）。

A.他有权要求施工单位为他办理意外伤害保险

B.如果办理意外伤害保险，则保险费由分包单位支付

C.如果他在工程竣工验收的过程中因公受伤，则不属于意外伤害险的承保范围

D.必须遵守项目负责人的一切指令

下列不属于数据库运行过程中可能发生的故障是

A．系统故障

B．事务故障

C．违背完整性约束条件

D．磁盘故障

如何保证挖掘机涉水作业时的安全？