例句與造句

1. No topology is needed to define a dense submodule, and a dense submodule may or may not be topologically dense in a module with topology.
2. No topology is needed to define a dense submodule, and a dense submodule may or may not be topologically dense in a module with topology.
3. It's difficult to find dense submodule in a sentence. 用dense submodule造句挺難的