It is required that the machine___ as frequently as necessary.
举一反三
- It is required that the machine ______ as frequently as necessary. A: be oiled B: must be oiled C: is oiled D: will oil
- It is required that the machine___as frequently as necessary. A: will oil B: be oiled C: is oiled D: will be oiled
- An indication of the space required is not usually necessary for registration.
- （）5. For plastic machine setters, formal training programs are always necessary.
- The<br/>necessary condition for A compiler on machine a to be used directly<br/>on machine B is that the operating system functions of machine a and<br/>machine B are identical.() A: True B: False