How can u apply in th real world next genration sequencing

Five examples of real-life situation that show a sequence are given as follows;

1) The progression from class to class in nursery, primary, and secondary

2) The annual increase in population of a country

3) The growth rate of living things

4) The annual weather cycles

5) The variation of temperature with altitude in the Earth's atmosphere

answer; ////increased water pollution; ///////////////////////

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.