You will not know who your true friend is _____. A. after you had had trouble and needed help . B. when you were having trouble and needing help C. until you have trouble and need help D. a4/61You will not know who your true friend is _____. when you were having trouble and needing helpwhen you were having trouble and needing helpuntil you have trouble and need helpas soon as you had trouble and needed helpGiải thíchChọn C