If someone is of the opinion that something is the case, that is what they believe.
[formal]
Frank is of the opinion that the 1934 yacht should have won.
معتقد بودن، عقیده داشتن، باور داشتن به چیزی
[formal]
Frank is of the opinion that the 1934 yacht should have won.
معتقد بودن، عقیده داشتن، باور داشتن به چیزی