A Reply from ELS Podcast

I listen to English as a Second Language Podcast (http://goo.gl/Qih6) in order to improve my listening comprehension.
In the ESL Podcast they answer some questions from listeners. There are many questions about how to use similar words or expressions.
I'd like to know how to use the words work, job, occupation and task, so I sent questions to ESL as follows.

Hello Jeff
I am listening to your podcast, and it is very helpful to improve my English. Thank you very much.
I have two questions about English.
The first one is what is different between the words work, job, occupation and task.
The second one is as follow.
I heard from a native speaker that sometimes I could use "they" as first-person singular pronoun
when I didn't know someone's gender.
Is it true or common usage?
I will be happy if you answer my question.
Yagian, Japan

Tomorrow I got a reply from ESL as follows. Some parts of it are routine, but some parts are a reply for my e-mail which they have read. I'm impressed with good services of ESL.

Dear Yagian,
Thank you for your kind message. We're glad you find ESL Podcast useful.
We appreciate your questions, too. If there is time, we will try to answer them on a future Café. We record our podcasts many weeks in advance, so if we include it, it may be a little while before you hear it. (Unfortunately, we are not able to answer all of the good questions we get from our listeners.)
Many of the questions we receive by email have already been answered on either a podcast episode or a blog post. For example, we discussed the meaning of work vs. job. vs. occupation here:
Also, most questions about vocabulary can be found in online dictionaries such as this one here: http://www.ldoceonline.com/
For future questions, please search our site first before emailing us your question. You may find that we have already answered it!
We really appreciate you taking the time to send us a message. Your support is very important to us, and thanks for listening.
ESL Podcast Team

I immediately began to use Longman's on line dictionary (http://www.ldoceonline.com/), when I write in English.