If the reaction took hours, and not seconds., the fuel costs would be prohibitive.

假如这一反应需要数小时而不是几秒钟，那么燃料成本就太高了。

youdao

If the reaction took hours, and not seconds., the fuel costs would be prohibitive.

假如这一反应需要数小时而不是几秒钟，那么燃料成本就太高了。

youdao