I like this comment which is one of highest rated ones.

When NASA first started sending up astronauts they quickly discovered that ball-point pens would not work in zero gravity. To combat the problem, NASA scientists spent a decade and $12 Billion to develop a pen that writes in zero gravity, upside down, underwater, on almost any surface including glass and at temperatures ranging from below freezing to 300 C. The Russians used a pencil.

所有跟帖： 

• 咋一看，还以为NASA花了天文数字的钱做了件蠢事，其实不然。 -00zz7788- ♂ (9774 bytes) () 02/09/2011 postreply 10:59:41

• 多谢科普。那个笑话本来就有夸张渲染成分。 -满地找牙- ♂ (0 bytes) () 02/09/2011 postreply 11:41:29

• 客气了。在分享你提供的信息之前，许多内容我是一五数字。 -00zz7788- ♂ (0 bytes) () 02/09/2011 postreply 11:54:00