Which country in Group B can be added to Group A? Why? It has nothing to do with their spelling or pronunciation.

Group A: Australia, Denmark, Egypt, Venezuela
Group B: Bulgaria, Japan, Peru, Sri Lanka, Thailand, Zaire

An anagram riddle to tease you;
Three five-letter words, each gets one clue.
A guillotine's use,
An act to get deuce,
And what you are reading now in view.

What are the words?

Five words that contain GH as a letter-pair have had all of their other letters removed and placed into a pool. Put those letters back in their proper places. What are the words?

GH---, -GH---, ---GH-, ----GH, ---GH--

Pool: A, A, E, I, M, O, O, O, R, R, S, S, S, T, T, T, T, U, U, W

Each of the following clues describes two words. One of the words is a type of tree. The other word is that tree with one of the following changes: a letter added anywhere (pine spine), a letter deleted anywhere (larch arch), a letter changed anywhere (birch birth). There is no rearrangement of the other letters. No tree is used more than once.

1) This is an older tree.
2) This is a well-known tree.
3) This is a feeble tree.
...

Which country in Group B can be added to Group A? Why? It has nothing to do with spelling or pronunciation.

Group A: Argentina, Dominican Republic, Ethiopia, Malaysia
Group B: Cambodia, France, Greece, Norway, Portugal, Somalia

I am a fake stone,
I am green without envy.
I am three in one,
I can symbolize the Trinity.

What am I?