Definition: a very small amount of a quality Level: C2
他的借口没有一丝真实性。
His excuse didn't contain a ___grain of truth.
她的理论包含一点真实成分，但主要是猜测。
Her theory contains a ___grain of truth but is mostly speculation.
没有任何证据支持那个说法。
There's not a ___grain of evidence to support that claim.
