英和和英

an angle of 10 arcseconds

vibrations per second

a duration of time lasting one second

Two seconds.

A period of two seconds.

frequency per minute

every second

one trillionth of a second

Fifteen seconds

Sixty seconds make a minute.

cycles per second

one thousand periods per second

thirty respirations per minute

one million periods per second

count down to liftoff

1,000,000,000 periods per second

a ten‐second delay

6 times per minute

have a lead of 20 seconds

one thousandth (10^-3) of a second

a flow of five gallons a second

the distance that an object moves in a second's time

50 miles a [per] second

3 seconds flat

one trillion periods per second

How far does it go in one femtosecond?

within 10 seconds

row 20 to the minute

the number of seconds counted in a knock out

per minute