можно допустить, что

• Conceivably some linings will be effective for as long as 50 years, but ultimately one must expect them to fail.

• If the earth consisted of a perfectly spherical lithosphere, it is conceivable that the entire lithosphere could move as a whole with respect to the rest of the earth.

• Perhaps one can concede that a single molecule might be formed in the postulated manner, but it is most improbable that ...