to work very fast because you know you only have a limited period of time to do something.

Scientists were working against the clock to collect specimens before the volcano erupted again.

• have a lot going for
• have a lot going for you
• have a lot irons in the fire
• have [a lot of/a few/several etc.] strings to bow
• have [a lot of/a few/several etc.] strings to your bow
• have a lot of strings to bow
• have a lot of strings to your bow
• have a lot of time for
• have a lot of time for someone
• have a lot of time for something
• have a lot on plate
• have a lot on your plate
• have a lot to answer for
• have a memory like an elephant
• have a memory like a sieve
• have a mind like a sieve
• have a mind like a steel trap
• have a mind of its own
• have a minute to call own
• have a minute to call your own
• have a monopoly on
• have a monopoly on something
• have an ace up sleeve
• have an ace up your sleeve
• have an axe to grind