Wood is the main raw material of pellets, but not the only one.

木材是颗粒的主要原料，但不是唯一的。

youdao

In the acid hydrolysis, xylose is the main raw material for preparation of xylitol.

在稀酸中水解，得木糖，是制备木糖醇的主要原料。

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Asphalt concrete has increasingly been adopted as the main raw material for road construction, but some problems have also emerged.

沥青混凝土已越来越多地被采用为公路建设的主要原料，但是不置可否也出现了一些问题。

youdao

Iron ore, the main raw material of steel, changed the lakes area and the nation.

VOA: special.2009.11.11

Mr Morales used to grow coca leaves - the main raw material for the drug but also a key part of indigenous traditions in Bolivia.

BBC: President Evo Morales on 10 March 2011

Plant oils consist of fatty acids combined with glycerol and these fatty acids (for example, those from palm oil) are the main raw material for the biodiesel already sold today.

ECONOMIST: Advanced biofuels

For 3, once nylon had been discovered and proven useful, the race was on, given the supply of cheap oil (the main raw material) post WWII, from the Arabian Gulf.

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