threaten the nation's existence
国家の存続を脅かす
three abreast seating
3人掛け
Three and five equal(s) eight.
3たす5は8(◆A=Bという式はA equals B. ともA is equal to B. とも読める)
Three and seven make(s) [equal(s), is, are] ten.
3+7=10
three bearings (in) a year
年3回の収穫
three billion
30億
three changes of clothes [underwear]
着替え[下着の着替え]3組
Three cheers for the President!
大統領のために歓呼三唱(◆Hip,hip,hurray [hooray, hurrah]!と3度言う)
three consecutive days
3日連続
three days [months] after ...
…して3日[月]後に