请解析英语单句改错（已有答案）为什么这样改?及有关语法句法,

请解析英语单句改错（已有答案）为什么这样改?及有关语法句法,
1,Like most people ,I was brought up to 【look upon (A)】life as a process of getting .It was 【not until(B)】 in my late thirties 【did I make】 (C)this important discovery:giving away makes life so 【much more(D)】 exciting.
C 改为 that I make
2.Planes are 【the fastest (A)】 way 【to transport (B) 】food.They are especially useful carrying food to people and animals 【that can not(C)】 【be reached (D)】otherwise
C 改为 that could not
3.He got up,walked across the room,【and with (A)】【a(B)】sharp quick movement 【flung (C)】the door【widely (D)】open
D 改为 wide open
4.【At (A)】 a mini mum,the negotiators are 【hoping to achieve (B)】 an agreement an agreement 【in principle (C)】,【with details worked out (D)】later
D 改为 with details to be worked out
5.【In note-taking (A)】,a strict discipline has 【to be kept (B)】and all inessential details 【ignored (C)】 and unnecessary words 【eliminated (D)】
B 改为 to be kept to