In this task, you are given a sentence. You are expected to write the name of the organism substances in the body mentioned in the input. Although there might be several correct answers, you need to write one of them.

Q:  Seven day point - prevalence abstinence will be determined by combining self - reported tobacco use over the prior seven days and urine cotinine assays ( below 200 ng / ml versus 200 or above ) .

A: urine
****
Q:  Lower peak blood ethanol concentrations after 1 and 2 g of ethanol per kg were found in pregnant rats than in virgin females .

A: blood
****
Q:  For the 30 cases of benign lesions of the GB , only in 12 cases was a low velocity blood flow signal found .

A:
blood
****