необходимо

см. тж. для этого необходим; когда это необходимо; нужно; следует

• There is a need to examine the significance of ...

• If steroids are used it is essential to reduce the dose as soon as possible to 7.5 mg of ...

• The bed needs (or has) to be regenerated before it can be used for another 10-min adsorption cycle.

• A very powerful magnetic field is required to ...

• It is essential that the insulation should be well packed.

• Much needs to be done to satisfy these requirements.

• Much remains to be done in this area.

• It takes a very powerful magnetic field to control the path of a particle.