再和大家强调一下：2019英语专四听力理解Section A: Talk本部分由一个500个单词的微型讲座(mini-lecture)和一项填空任务组成。要求学生边听边做笔记，然后完成填空任务。考试时间10分钟。本部分共10道填空题。
[00:01.39]SECTION A TALK
[00:03.91]In this section you will hear a talk.
[00:07.28]You will hear the talk ONCE ONLY.
[00:11.71]you may look at ANSWER SHEET ONE
[00:14.01]and write NO MORE THAN THREE WORDS for each gap.
[00:18.38]Make sure the word(s) you fill in
[00:21.54]is (are) both grammatically and semantically acceptable.
[00:27.22]You may use the blank sheet for note-taking.
[00:30.89]You have THIRTY seconds to preview the gap-filling task.
[01:06.46]Now listen to the talk.
[01:08.63]When it is over, you will be given
[01:10.69]TWO minutes to complete your work.
[01:15.66]5 Tips to Know Before Your First Lab Class
[01:20.59]As students, you do much of your learning
[01:23.46]sitting inside a classroom,
[01:25.72]listening to an instructor lecture.
[01:28.83]Such learning can sometimes feel repetitive and boring.
[01:34.12]Thus, many students are excited by the fun
[01:37.38]and the hands-on opportunity to learn.
[01:40.54]However, they can also become dangerous rather quickly
[01:44.57]if the proper safety precautions
[01:46.83]and lab regulations are not respected.
[01:50.49]To help make sure you stay safe,
[01:53.26]please follow five tips
[01:55.27]before stepping foot inside your first lab class:
[01:59.65]First, make sure you understand the experiment before it starts.
[02:05.93]Before leading an experiment,
[02:08.20]your teacher will likely review the instructions that
[02:11.47]you and your classmates are to follow in the lab.
[02:15.39]Besides verbal instructions,
[02:17.61]you will also typically be provided with a printed guide,
[02:21.79]often with diagrams and illustrations,
[02:24.71]explaining the experiment in detail.
[02:27.98]While your teacher reviews the instructions,
[02:30.79]it's critical to follow along
[02:33.01]so that you know how to perform the experiment safely
[02:36.27]and accurately once class begins.
[02:39.84]Second, wearing the right kind of clothes
[02:43.30]and gear in the lab helps keep you safe.
[02:46.87]Because each experiment involves
[02:49.63]the use of different equipment and chemicals,
[02:52.35]which vary in their degree of hazard,
[02:54.96]your teacher should provide you with detail on
[02:57.88]what to wear to each class, depending on the experiment.
[03:02.21]In general, however, you should never
[03:04.87]wear open-toed shoes in the lab.
[03:07.89]To mitigate the chance of you catching on fire,
[03:11.01]remove loose clothing, like scarves,
[03:13.87]and roll up long sleeves.
[03:16.19]To that end, you should also remove any dangling jewelry,
[03:20.15]and if you have long hair, tie it back.
[03:23.22]Always wear a lab coat or apron, gloves,
[03:26.93]and goggles when handling chemicals.
[03:29.69]Third, be aware of safety equipment
[03:33.42]and where it's located.
[03:35.47]Some common types of lab safety equipment
[03:38.34]include emergency eye-washers and emergency showers,
[03:42.77]which should be used when chemicals
[03:44.59]get into the eyes or on one's skin; exhaust hoods,
[03:48.90]which are used to divert
[03:50.31]dangerous chemical fumes and smoke;
[03:52.61]and fire blankets and fire extinguishers,
[03:56.15]which are used to douse fire.
[03:58.56]You should know how to use each
[04:01.20]so that you can react appropriately if an accident does occur.
[04:06.35]Fourth, fill out your lab form
[04:09.34]as you conduct your experiment.
[04:12.05]Often, this form is part of the lab instructions.
[04:16.79]When conducting the lab, fill out this form
[04:20.06]as you go along rather than trying to remember
[04:23.12]everything you did in the lab
[04:25.43]and filling it in after class is over.
[04:28.44]This will help ensure you don't forget
[04:31.41]to record anything important,
[04:33.82]such as a precise measurement or detailed observation.
[04:38.85]Fifth, complete your lab report
[04:42.01]as soon as possible after the lab.
[04:45.13]Lab reports are a more detailed analysis of your experiment
[04:49.31]and how it connects to a larger scientific concept.
[04:53.63]Though your teacher will typically give you a few days
[04:56.91]to a week to finish a lab report,
[04:59.82]it should be much easier to complete a lab report sooner
[05:03.89]rather than later as the experiment's concept
[05:07.20]and the steps are still fresh in your mind.
[05:10.88]Plus, finishing your lab report early
[05:13.95]will give you time to reread it, and revise it when necessary.
[05:18.76]Last but not least, we hope that you will find these tips
[05:23.28]useful and enjoy your first lab class. Thank you.
[05:29.81]Now you have two minutes to complete your work.
[07:34.07]This is the end of Section A TALK.