id	keyword
fbem-16456	speed rail
fbem-16456	green
fbem-16456	innovation
fbem-16456	opening
fbem-16456	enterprises
fbem-16456	environmental
fbem-16456	rail opening
fbem-16456	economic
fbem-16456	china
fbem-16456	variables
fbem-16456	research
fbem-16456	year
fbem-16456	impact
fbem-16456	uncertainty