Rewrite each original sentence in order to make it easier to understand by non-native speakers of English. You can do so by replacing complex words with simpler synonyms (i.e. paraphrasing), deleting unimportant information (i.e. compression), and/or splitting a long complex sentence into several simpler ones. The final simplified sentences need to be grammatical, fluent, and retain the main ideas of their original counterparts without altering their meanings.
--------
Question: Further, the term "The Celsius or Centigrade thermometer" was again used in reference to a particular type of thermometer at least as early as 1850.

Answer: The Celsius or Centrigrade thermometer was again used to refer to a particularly type of thermometer around 1850.

Question: ECW Background After World Wrestling Entertainment (WWE) bought all of Extreme Championship Wrestling (ECW)'s assets in 2003, the company began releasing DVDs promoting the original ECW.

Answer: After World Wrestling Entertainment bought Extreme Championship Wrestling in 2003, the company began making DVDs advertising the ECW.

Question: As the Church of Satan does not publicly release membership information, it is not known how many members belong to the Church.

Answer:
It isn't know how many members are in the Church of Satan as they do not release information to the public.