22895
The rotational spectra of three isotopologues of the 1 : 1 complex between difluoromethane and formaldehyde have been observed and assigned using pulsed jet Fourier transform microwave spectroscopy .
 Chemical: difluoromethane; Chemical: formaldehyde
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: difluoromethane, formaldehyde 
Answer:
 Chemical: difluoromethane; Chemical: formaldehyde