Sentence examples for be difficult and sometimes from inspiring English sources

A shortcoming is that it can be difficult, and sometimes impossible, to estimate the values of interest, for example the WTP for noise reduction at different times of the day [17].

The interpretation of results of serology for B. burgdorferi may be difficult and sometimes is indeterminate.

However, in the case of dioxins, there can be many different sources of exposure, and sorting out the actual source will generally be difficult and sometimes impossible.

However, one drawback is that sometimes in critically unwell patients, obtaining urine may be difficult and sometimes uNGAL may be elevated with urinary tract infection [ 14].

This is because it can be difficult, and sometimes, controversial to calculate a monetary value for children's health and development (Cellini and Kee 2010; Dhaliwal et al. 2012).

Indeed, insertion of the HindIII site has such a negative effect on IRES function that detection of the IRES-controlled product can be difficult, and sometimes even below the levels of detection.

It was difficult and sometimes dangerous work.

Celibacy is difficult and sometimes lonely for anyone.

Negotiation is difficult, and sometimes we make it even harder by creating extra roadblocks for ourselves.

The exhibition's argument is difficult and sometimes too allusively made, but the impact is considerable.

The Santa Monica cougars are hemmed in by freeways that are difficult, and sometimes deadly, to cross.