小明在学校参加植树活动时，使用如图12所示的钢丝钳，剪铁丝时钢丝钳是      杠杆(选填“省力”或“费力”)，拧螺丝时它是哪一种简单机械：        ；剪铁丝时动力臂长为10cm，阻力臂长为2cm，若铁丝被剪断需要克服1000 N的阻力，小明至少用       N的力才能将铁丝剪断。

Directions: You got sick just two weeks before the final examination and were sent to hospital. One doctor treated you very well and you recovered soon. Write a letter of appreciation to the doctor (Ms. Green).

You should write about 100 words on ANSWER SHEET 2. Do not sign your own name at the end of the letter. Use "Li Ming" instead. Do not write the address. (10 points)