Put the Stages of Primary Succession in Their Proper Order

Put the stages of primary succession in their proper order. Start by writing the letter of the first stage next to number 1, and so on.
A. bushes appear
B. ferns and grasses become established
C. glaciers retreat
D. lichens erode rocks
E. mosses appear
F. soil is present
G. trees are established
first event _________
second event _________
third event _________
fourth event _________
fifth event _________
sixth event _________
seventh event _________