There was an ( __ ) (engineer) problem of the machine.
举一反三
- The scientist and engineer ____ (have) invented a new machine. A: are B: was C: has D: were
- The engineer will take the _____of designing the machine. A: right B: power C: goal D: responsibility
- The ratio of the work done by the machine _________ the work done on it is called the efficiency of the machine.
- Never attempt to machine a work-piece without first checking the operation of the machine.( )
- If the engineer _________here yesterday, the problem would have been solved.