Sentence examples for and it is difficult to establish from inspiring English sources

Studying the links between pollution and health is difficult, since so many factors are involved and it is difficult to establish a direct cause-and-effect relationship.

Unfortunately the evidence is contradictory and it is difficult to establish any points with certainty.

However, there are many factors that influence the results of the experimental tests, and it is difficult to establish whether the value obtained is really representative of the material in situ and if there are alterations which have arisen in time.

The majority of studies of use of delivery care are cross-sectional and it is difficult to establish time sequence.

Under these conditions, the sensitivity of parasitological tests is very low and it is difficult to establish a clear diagnosis.

Nevertheless, the latter may also facilitate arrhythmias through Ca2+ handling abnormalities (see below) and it is difficult to establish which mechanism prevails in a specific condition.

Therefore it is difficult to establish cause and effect.

However, it is difficult to establish a relationship between the wear performance and TRS.

It is difficult to establish an adequate system of law in China and requires more effort".

But, Ms. Marsh said, it is difficult to establish many plants without regular watering.

If there is no access to credit, it is difficult to establish a viable business.