Some products are carefully designed to make the products convenient and efficient, can bring customers a sense of comfort, and do not need to read complicated instructions or ask others for help when using them. Some products, on the contrary, do not take into account the user's habits and needs. People will encounter difficulties or puzzles during use. This type of product is known as the Norman product. According to the above definition, which of the following is Norman products? ['The quality of the bottom pulley of a large wooden wardrobe is poor, and it is difficult for users to pull the door open.', 'It is difficult to clear a certain online game. Many players ask for help online to crack the levels.', 'The shape and size of the car radio button and other device switches are the same, it is difficult for users to distinguish which one is the radio button.', 'There is a 300-page manual attached to the precision experimental equipment of a technology company. Most people think that there are too many terms in it and it is difficult to read.']