Before _____, the machine must be checked.
举一反三
- Before _____, the machine must be checked. A: being used B: using it C: being used to D: using
- High-level languages must first be translated into a machine language before they can be understood and processed by a computer. This job is often done by ( )
- The washing machine ______ before it can be used. A: must repair B: needs repairing C: should be in repair D: require be repaired
- It is essential that all these figures ______ twice. A: must be checked B: be checked C: is checked D: will be checked
- Each ______ is carefully checked before assembly.