translation.en: So I proposed my idea to improve the situation using these recycled paper tubes because this is so cheap and also so strong, but my budget is only 50 U.S. dollars per unit.
translation.zh: 于是，我提出了利用这些再生纸管 来改善现状的想法 因为纸管便宜又坚实。 但我的预算只有每个50美元。