What do these symbolize in the british coat of arms?
1.Red lion holding the Honours of Scotland - the Scepter and the Sword of State...
2.Crowned English lion
3.Fleurs-de-lis
4.Lion Guardant
5.Scottish lion rampant
6.Fleurs-de-lis
7.Irish Harp
8.Crowned English Lion
9.Unicorn

1.Red lion holding the Honors of Scotland: The crest atop the Crown of Scotland is a red lion, seated and forward facing, itself wearing the Crown of Scotland and holding the two remaining elements of the Honours of Scotland, namely the Sword of State and the Sceptre of Scotland. This was also the crest used in the Royal Arms of the Kingdom of Scotland.  

2.Crowned English lion: The Lion is the emblem of England. It is now, on badges, actually a "lion passant gardant" - a walking lion, looking out at you full face, and was first used by Rollo, Duke of Normandy (father of William the Conqueror, who added the second lion to the Royal Coat of Arms for England.)

3. Fleurs-de-lis: The French monarchy possibly adopted the Fleur-de-lis for its royal coat of arms as a symbol of purity to commemorate the conversion of Clovis I, and a reminder of the Fleur-de-lis ampulla that held the oil used to anoint the king. So, the fleur-de-lis stood as a symbol of the king's divinely approved right to rule.

4.Scottish lion rampant: It seems that the rampant lion design was first used as a symbol of the Scottish kingdom by King Alexander II (1214 - 1249 AD). It appeared as a coat of arms on one of his seals in 1222, and also later, on a seal of Alexander III.

5.Irish Harp: An Irish harp appears on the Royal coat of arms of the United  Kingdom to represent Ireland's place in the UK. The shield is  quartered, with the guardant lions of England filling the first and   forth quarters, the rampant lion and double treasure  flory-counterflory of Scotland in the second, and the Irish harp in  the third. The Irish harp is the featured element on the coat of   arms of Ireland.

6.Crowned English Lion: The dexter supporter is a likewise crowned English lion; the sinister, a Scottish unicorn. According to legend a free unicorn was considered a very dangerous beast; therefore the heraldic unicorn is chained, as were both supporting unicorns in the royal coat of arms of Scotland.  

7.Unicorn: The Lion and the Unicorn are symbols of the United Kingdom. They are, properly speaking, heraldic supporters appearing in the full royal coat of arms of the United Kingdom. The lion stands for England and the unicorn for Scotland.

Explanation:

I hope this helps in some or any way.      

d. cassius cannot believe that a weakling like caesar has become so great.