Do you understand the (meaning) of the new world?括号里为什么要填ing形式

How do you understand Once the sands have run out of a person'shourglass,th Do you understand me? Do you understand Do you understand? Do you understand you do not understand do you understand答语 Do you understand是什么意思? do you understand Do you understand? are you understand 还是do you understand do You understand 怎么发音 Do you understand?译成中文 Because you do not understand! do you understand的意思 Who do you understand me? did you understand 和 do you understand 的用法区别 Are you understand正确还是Do you understand正确?