I

см. тж. целесообразно

• Before beginning this task it would be well (or we would do well) to consider ...

• It turns out to be profitable to deal with ...

• It is worthwhile to be able to predict whether or not ...

• It is helpful (or advisable, or useful) first to consider a simpler system.

• It is good (or sound) practice [or It is wise (or well)] to rinse off the solution.

• It may be beneficial (or useful, or expedient, or advantageous) to reduce the mass velocity.

II

• To see the relative role of ... , it is instructive to compute these parameters for a 1 metre cuvette.

см. тж. быть полезным; весьма ~

• This knowledge is useful to the biologist.

• The ladybird beetles are among the most beneficial of all animals because ...

• The usable length of the thread ...

• This feature of the centrifugal pump may be of advantage (or of use, or useful, or helpful, or beneficial, or advantageous) where the quality delivered must be ...

• These effects may be of utility (or of service) to the organism in times of violent effort and emotion.