完成句子：(共5小题，10个空，每空1分，满分10分)
When the war ______  ______ (爆发), he was working in the navy.
I can’t ______  ______(想出)why she said that.
______  ______he is free will he come to see me.
______  ______ a good teacher, John made great progress in his English study last term.
If I have a choice I would ______  ______ choose something else.