填空题 To protect his new invention,he took out a patent（）it.
on

正确答案

take out a patent on sth.取得一项……的专利。另外hold a patent on对……拥有专项权利。句意：为了保护他的发明，他申请了专利。

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填空题 To protect his new invention,he took out a patent（ ）it. on