设备声级检测测量相邻测点声压级差值应不大于（），否则需要增加测点。 A.3dB（A）

Does this situation seem familiar to you? Your English is progressing well, the grammar is now familiar, the reading comprehension is no problem, and you are speaking quite fluently.  _ 小题1: 

First of all, remember that you are not alone. Listening is probably the most difficult job for almost all learners of English as a foreign language. The most important thing is to listen as often as possible.

__小题2:The Internet is really a useful tool for English students. You can download The RealPlayer from RealMedia.com. The RealPlayer allows you to use the Internet like a radio station.

Once you have begun to listen on a regular basis, you might still be frustrated （受阻）by limited understanding. __小题3:_

Here is some of the advice I give my students:

●Accept the fact that you are not going to understand everything.

●Stay relaxed when you do not understand, and try listening to the material for more times.

● Do not translate everything into your native language.

● _小题4:__ Don’t concentrate on details before you have understood the main ideas.

● Listen to something you enjoy.

I remember the problems I had in understanding spoken German when I first went to Germany. In the beginning, when I didn’t understand a word, I insisted on translating it in my mind. This method usually resulted in confusion.   小题5: Firstly, translating creates a barrier between the listener and the speaker. Secondly, most people repeat themselves constantly. By remaining calm, I noticed that even if I didn’t pay much attention I could usually understand what the speaker had said.

A．But you can’t follow a native English speaker at all!

B．What should you do?

C．But listening is a problem for most of the beginners!

D．However, after several weeks, I got used to the new environment in Germany.E. So, what you need to do is to find listening resources.

F. Then, after the first six months, I discovered two extremely important facts.

G. Listen for the general idea of the conversation.

患者，女，35岁，右上颌中切牙近中面中龋，缺损面较大，曾行树脂充填美观效果差，但未及髓，热测有正常反应，要求金属烤瓷冠修复。

牙体预备时，为保证美观和冠边缘的强度，唇侧肩台的宽度一般应为（）

A.0.5mm

B.1.0mm

C.1.5mm

D.2.0mm

E.2.5mm

一种比黄金贵百倍的¹⁸O₂气体，不久前在兰州近代物理研究所研究成功。1 mol这种¹⁸O₂气体中含中子的物质的量为(　　)。

A．10 mol

B．16 mol

C．20 mol

D．36 mol

有关脊麻时低血压的原因，哪项正确()

A．阻滞交感神经节前纤维

B．阻滞支配肾上腺髓质的神经

C．阻滞副交感神经纤维

D．肌肉松弛

E．术前脱水

GSM系统主要哪三个子系统构成？