Неличные формы английского глагола. Коптева Н.Ю. - 51 стр.

      2. We may also point out that Eq (17.22) shows that the force
         from induced currents — that is, any eddy-current force — is
         inversely proportional to the resistance.
      3. These quantities may also be found by an optical experiment.
      4. So we have the very useful general fact that whenever you
         have to take the gradient of a vector that varies as a wave in
         three dimensions (they are an important part of physics), you
         can always take the derivations quickly and almost without
         thinking by remembering that the operation is equivalent to
         multi plication by — ik.
      5. There may be times, however, when in working on some
         problem you have only some equations and you may not see
         right away what physical arguments to use.
      6. It is an indirect effect which can be explained only by quantum
         mechanics.
      7. Since it is a scalar, it should be the same for any orientation of
         the spin.

               Modal verbs followed by Perfect Infinitive
I.    Restate the following sentences using «must» with perfect infinitives.
      Follow the model.
      Sp.: They have to find a way to avoid such paradoxes.
      St.: They must have found a way to avoid such paradoxes.
      1. They have to diminish the pressure.
      2. They have to perform the calculations in time.
      3. They have to study classical liquid structure.
      4. Liquid crystals should be used in technology.
      5. They have to limit the heat produced to the proper amount.
      6. He must exert every effort to perform the task.
      7. The producers are to supply the demands of consumers.
II.   Restate the following sentences using «may» with perfect infinitives.
      Follow the model.
      Sp.: It is probable that the demand for this equi pment has
           subsided.
      St.: The demand for this equi pment may have subsided.
      1. They have probably referred to the matter again.
      2. It is likely that they have obtained the necessary data.
      3. It may be that he has described the results of the experiment.
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