例句與造句

1. Some early " portal " appearances in science fiction include A . E . van Vogt's novella " Secret Unattainable " ( July 1942 Ramsbotham jump ".
2. A Malthusian catastrophe on Earth has been averted by the invention of teleportation, called the " Ramsbotham jump ", which is used to send Earth's excess population to colonize other planets.
3. It's difficult to find ramsbotham jump in a sentence. 用ramsbotham jump造句挺難的