During the exam, the answer sheet can be made of black neutral carbon pen and black signature pen.
A pen is a writing instrument mainly made of metal. It contains ink (mostly black or blue) through a hollow pen tube, and then writes through a duckbill pen through gravity and capillary action. It can be said that it is a writing tool of western calligraphy. Most pens can be replenished with ink. Generally speaking, vials or straws such as eye drops are used to supplement the kit. The earliest historical record of fountain pen can be traced back to 10 century, and this earliest fountain pen has been used until 18 century. The development process was very slow, but it was not until the beginning of the 9th century that a pen with stable and accelerated flow was invented in the production process. Only three key inventions have made the pen a widely popular writing tool. These inventions are: gold nib made of iridium, hard rubber and free-flowing ink.