IEEE 802.1标准主要包括哪些内容( ) Ⅰ．局域网体系结构 Ⅱ．网络互

水晶的主要成分为二氧化硅（SiO₂），其中硅元素的化合价是（　　）

A．+2

B．+3

C．+4

D．+5

预算法规定：预算由预算收入和预算支出组成。预算收入包括（）。

A.税收收入

B.依照规定应当上缴的国有资产收益

C.专项收入

D.其他收入

下列方法中属于定性预测技术的是( )

A．德尔菲法

B．趋势分析法

C．比率分析法

D．回归预测法

前列腺增生CT、MRI表现叙述错误的是（）

A.CT平扫前列腺内可见点状钙化

B.增生前列腺结节T₁WI呈均匀低信号

C.增生结节T₂WI一定呈高信号

D.增生结节增强扫描多明显不均匀强化

E.CT可见增大的前列腺突入膀胱底部

Are you dreaming of taking a trip on your own Here is some advice on how to make your once-in-a-lifetime journey and how to stay safe when you get there.

Before you begin to look at places, activities and plane tickets, you must set a budget. When you search through the websites about travelling, it can be so easy to add another week here or there, or choose an extra activity. Setting a budget can avoid creating a huge bill, which starts very small.

With so many countries on this planet it is difficult to decide where to go. By narrowing down your search to voluntary work or a relaxing holiday, you can save a lot of time looking through websites.

After deciding where to go, you need to research the country. Find out when each season is. It would be disappointing if you were taking part in an outdoor-based activity and it rained most days. Look into medical information, as you may need certain medicine for certain countries. Above all, make sure you can afford to go to this country and take part in the activities you have dreamt about. Don’t raise your hopes too high before you know for certain it is within your budget.

By carrying a credit (信用) card with you at all times it is possible to stop yourself getting lost. Mobile phones are very important as well. However, do not depend completely on them, since electronic machines can break without warning. Therefore, always carry a list of emergency (紧急情况) phone numbers, names and addresses. Finally, learn a little of the language. Do not expect that the people there speak your own language. After all, you are in their country.

What is the best title for the passage().

A．Take a Relaxing Trip

B．Save up to Travel Alone

C．Create a Pleasant Trip

D．Prepare for Travelling Alone