Some replacement parts are being hand-carried back into Iran by those traveling from other countries.

一些替换零件由来自其他国家的人手工带回伊朗。

However, this also implies that replacement parts and consumables used in a diesel engine are more expensive, and contribute to higher maintenance costs.

然而，这也意味着柴油发动机中使用的替换零件和消耗品更昂贵，并导致更高的维护成本。

He drafted a prototype for a transportation company that would guarantee overnight delivery of small, time-sensitive goods, such as replacement parts and medical supplies, to major US regions.

他设计了一份运输企业的经营草案，该运输企业可以确保连夜递送小型或时间紧迫的货品到达美国的主要地区，如替换零件、医药用品等等。

But researchers say that even some of the recently built fuel-powered plants are out of service because of a lack of fuel, delayed repairs, and lack of replacement parts.

但研究人员表示，即使是最近建成的一些燃料发电厂也因燃料短缺、维修延误和缺乏更换零件而无法使用。

If you say 'Replacement parts are hard to get hold of', you mean that it's difficult  to find a shop or website which sells them.

如果您说“更换零件很难买到”，您的意思是很难找到出售它们的商店或网站。