1、He proved himself a true gentleman and the beauty of his -

1、He proved himself a true gentleman and the beauty of his ______was seen at its best when he worked with others.A、temper B、appearance C、talent D、character 这题的正确答案是D,为什么A不对?2、No one in the department but Tom and I_____that the director is gong to resign.为什么中间要用knows而不能用know?3、I am sorry I step outside for a smoke.I was very tired.------There is no ____for this while you are on duty.为什么这题要写用excuse而不用reason?4、The warmth of _______sweater will of course be determined by the sort of wool.A、the；the B、the；/ C、/；the D/；/这题为什么要选B而不选C?还有就是stationery是什么意思?