The magnitude and impacts of desertification vary greatly from place to place, and change over time.

Evaluations of particular outputs and projects are done from time to time but they vary in quality and peer reviews are sporadic.

Hence, we write the position element as formula_81 and the velocity element as formula_82, indicating that they vary with time.

The point is that economic behavior is complex and can vary among individuals, over time, between goods, and across cultures.

The weight given to each of these factors depends on circumstances and priorities, and should vary by country and time.

Explanations vary.

Unlike capital flows, which vary according to the economic environment, remittances tend to stay stable and are less volatile over time.

For most stars the convective zones will also vary over time as the star ages and the constitution of the interior is modified.

Of course, the terms of the contract vary with place and time. In nineteenth century Europe, the rich were expected to be frugal.

Thus, the 243 year cycle is relatively stable, but the number of transits and their timing within the cycle will vary over time.

For example, at an altitude of , the atmosphere's density can vary by a factor of five, depending on the time of day, time of year, AP magnetic index, and recent solar flux.

The capacities of these ovens vary.

Criteria for brain death vary.

These balls vary in size.

Responsibilities vary in different companies.

The sources of light used may vary.

At the same time, to restart an economy s growth and employment engines, other measures are needed, and vary somewhat across countries, owing to different initial conditions.

The data vary considerably, depending on the source.

But local tastes nonetheless vary widely.

Ingredients and dishes vary by province.

These restrictions may vary by location.

However, the reasons for this vary a lot.

The fees vary for each of the managers contracted.

Their values vary from gas to gas.

Levels of compliance continue to vary, however.

The necessary balance may vary according to local conditions.

Causes of crashes vary according to local conditions.

Even so, income distributions vary widely among the developed countries.

Definitions of the poverty line do vary considerably among nations.

Ovens also vary in the way that they are controlled.

The nature and scale of threats inherent in hazards vary.

The current data on the population of New Caledonia vary significantly.

Their labor market, social welfare, and competition policies vary.

Admittedly, Arab countries problems vary by degree and type.

However, a payload may vary depending on military requirements.

They vary greatly in geographical distribution and demographic significance

As a result, they tend to vary between countries.

Assets grow with contributions and vary with investment performance.

This ratio determines whether or not the temperatures inside a body will vary significantly in space, while the body heats or cools over time, from a thermal gradient applied to its surface.

Tariff rates usually vary according to the type of goods imported.

The sources of marine waste vary from one country to another.

They may vary depending on the size and complexity of procurement.

The requirements of logistics and security can vary greatly between situations.

The height of a person can vary over the course of a day, due to factors such as the amount of exercise done directly before measurement (normally inversely correlated), or the time elapsed since lying down for a significant period of time (normally inversely correlated).

The actual percentage is likely to vary depending upon the subject matter.