Misc: What colour does a chameleon turn when its angry?

Questions

What si the name given to a semi circular recess behind the chancel containing the altar?

What is th ename of the huge 3 tiered roman aqueduct built in AD14 between Uzes and Nimes in France?

which British architect designed the 1995-9 alterations to the Reichstag in Berlin for which he was awarded the Pritzer Prize?

What are voussoirs?

What name is given to the wall of a mosque which faces Mecca?