You ...... (practise) your Chinese more often, David, or you'll get very rusty indeed.

Your son ...... (see) a specialist right away. He seems to be suffering a lot.

The navigator ...... (come) to the bridge now, or we may not escape the danger ahead.

The young architect ...... (ask) for advice more often if he doesn't want to discredit himself right at the start of his career.

The miners ...... (not / forget) their oxygen this time as they're going to work in a dangerous mine.

The co-pilot ...... (not / leave) the cockpit when the captain is not in.

The maid ...... (take) care of the rooms upstairs if she wants to keep her job.

The plane ...... (land) on time if the manager is to keep his appointment.

The army plane ...... (take) off right away if they want to get to Africa tomorrow morning.

You ...... (really / put) those petty problems aside for a moment, or you won't get the job done well, David.

Simon's grandfather ...... (make) an appointment with his GP and have himself examined. He's been suffering from the bad flu for quite some time now.

The professor ...... (arrive) at the hotel at 12.00 sharp if he wants to attend the afternoon party.