However， there was potential bias in the included studies， so the conclusion still needed further high quality（）（随机对照试验）to improve the evidence level.

However， there was potential bias in the included studies， so the conclusion still needed further high quality（）（随机对照试验）to improve the evidence level.
A.randomized treated trials
B.randomized controlled trials
C.randomized controlled examination
D.randomly controlled trials
正确答案：randomized controlled trials