The new method for refining metals was______that they became practical for many purposes,

There is ______ the fact that the new method has greatly raised labor productivity.A．not d

Whats the main feature of the new method of paying for meals？A．All students pay the same a

The phrase （) means "law that prescribes the procedures and methods for enforcin

The technicians and workers have come______new methods to increase production.A．on withB．o

Which is not necessary for every development method？A.The new system requirementsB.Testi

With the populationexplosion scientists will have to_______new methods ofincreasing the wo