英语语法分析

So far, Toyota has remained mum about its neodymium-free electric motor-generator.

到目前为止，丰田仍然对它的无钕电动发动-发电机保持碱默。

The rare-earth element that other industrial countries worry about most is neodymium.

其他工业国家所最担忧的稀土元素是钕。

The most problematic materials may be rare-earth metals such as neodymium used in turbine gearboxes.

真正棘手的原料是稀土金属，比如用在涡轮机变速箱中的钕。