1 two-dimensional barcode

2 QR code

1 number of people

1 to count backwards (from 10 down to 0)

2 to count down

3 from the bottom (lines on a page)

4 from the back (rows of seats)

1 (exam) grade

2 mark

3 score

4 fraction

1 majority

2 most

1 one scare after another (idiom)

2 in a constant state of tension

1 lit. their number cannot be counted (idiom); fig. countless

2 innumerable

1 Destiny is inexorable, there is no fleeing it (idiom). Your doom is at hand.

1 everyone participates in reforms (idiom)

2 to replace the old with new

3 to reform and start afresh

1 lit. as if enumerating one's family valuables (idiom)

2 fig. to be very familiar with a matter