There is a persistent urban legend that a duck's quack does not echo, and I suspect that's what you're thinking of.It's not true. No bird has a call that does not echo.http://www.straightdope.com/columns/read/1090/is-it-true-a-ducks-quack-wont-echo
Female ducks make a more distinct quack, whereas males will all make more of a raspy quack. This holds true for most all breeds of ducks.
Not all are true. Some are false, because the Snapple writers have not done their research! For example, #36: a ducks quack does not echo. A duck's quack DOES echo, it just isn't very distinctive. There is a link to a Wikipedia article where the incorrect "facts" are discussed below. Also, Real Fact #0 says that half of the "real facts" are false.
The movie Echo is a work of fiction and not based on a true story.
Peking Duck is a famous dish from Beijing, China. It is strips of roasted duck served with shredded vegetables and a sweet sauce. It can be ordered from all Chinese restaurants.
true
True
yes
Quite.
Print always returns a value of true, but echo doesn't. echo also has a short cut syntax meaning you can immediately follow the php tags by an equals sign and it will echo the result like in the example shown below: <?=$hello?>
Not true, it has a filter.
Who ever put this is wierd and that is not true