Sentence examples for usually difficult to identify from inspiring English sources

However, prior knowledge is usually difficult to identify.

But unlike many other harassment cases, it is usually difficult to identify the culprits because most nooses are left anonymously.

The full effects of needle reuse are usually difficult to identify given the lack of patient surveillance and the long latent periods of target diseases.

Though usually difficult to identify in areas of overlap with other large skua species, the South Polar Skua can be identified by its contrasting plumage dominated by cold tones (no rufous), dark wings with the characteristic white "skua flash" along the primary bases, and pale feathering at the base of the bill.

However, it is usually difficult to identify the source of infection.

It was usually difficult to identify a point in the discussion at which a clear decision was made.

Dural AV fistulas (DAVFs) are usually more difficult to identify than AVMs on conventional MRI, especially when venous ectasia is absent, as in type I and II DAVFs; the patients have vague symptoms (i.e. headache or tinnitus) and there are no localising signs [29].

On the contrary, DIFFERENT errors were sometimes (32.1% of times, 9 pairs out of 28) associated to mistakes made in identifying musical notes corresponding to black keys, which are usually more difficult to identify.

However, parallel evolution can result from other processes, which are usually ignored or difficult to identify, such as developmental constraints.

Crypts in the rabbit colon are often separated by only a few micrometers of lamina propria, usually making it difficult to identify single crypts in the en face images.

As a result, the size of the sample is usually limited and microfractures are difficult to identify.