equipoise       
noun [ U ]  formal uk/ˈek.wɪ.pɔɪz/ us/ˈek.wɪ.pɔɪz/
 平衡;均势
a situation in which things are perfectly balanced
  There is in the artist's landscapes a delicate equipoise between the natural and the man-made. 在艺术家的风景画中,自然与人为之间有一种微妙的平衡。 
 If the evidence for and against the defendant's guilt is in equipoise, then the burden of proof is on the prosecution.  如果支持和否定被告有罪的证据相当,那么举证责任由控方承担。