A.
ti=((straw* or stalk*) and fermentation and (ethanol or bioethanol))
B.
ti=((straw* or stalk*) and fermentation and (ethanol* or bioethanol*))
C.
ts=((straw* or stalk*) and fermentation and (ethanol* or bioethanol*))
D.
ts=((straw* or stalk*) and fermentation and (ethanol or bioethanol))