Dallas: [looks at a pen being dissolved by alien's body fluid] I haven't seen anything like that except, uh, molecular acid.
Brett: It must be using it for blood.
Parker: It's got a wonderful defense mechanism. You don't dare kill it.
Brett: It must be using it for blood.
Parker: It's got a wonderful defense mechanism. You don't dare kill it.
Dallas : [looks at a pen being dissolved by alien's body fluid] I haven't seen anything like that except, uh, molecular acid.
Brett : It must be using it for blood.
Parker : It's got a wonderful defense mechanism. You don't dare kill it.
http://www.moviequotedb.com/movies/alien/quote_26917.html