Sentence examples for difficult to preserve over from inspiring English sources

However, faecal pools are difficult to preserve over longer periods of time, and therefore the inclusion of larger numbers of observers would be impossible.

When the amount of occurrences and circumstances that require acting or responding during the week increases, people's mental capacity of handling other tasks may be reduced, and a focus on cessation efforts may be difficult to preserve over time.

In the last 14 years the search giant has gone from two employees to over 32,000, making it difficult to preserve its nimble and industrial start-up days.

Consequently, epithelial integrity is difficult to preserve due to the tremendous loss of proliferative cells over a short period of time.

That makes it difficult to preserve vacant space".

It is difficult to preserve something that was made to vanish".

But the French Revolution proved that it is difficult to preserve epic economic imbalance.

Even in our visually rich digital age, a dance is difficult to preserve.

Eggs and embryos, because of their much larger size, are even more difficult to preserve.

But "peace" was difficult to preserve on both the domestic and foreign fronts.

This indicates that it is difficult to preserve well-defined zigzag edges for the mass-production of GQDs.