Make riddles of an Entrance Door

People knock me to call you,but you locked me if you go to somewhere? What am i?
Answer:Front Door/Entrance door

Answer;
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When you want to enter into the room either home, office, school. You must be through it. The height varies from one to another, there are 2 meters, 3 meters, even more because it is adapted to the condition of the place, the shape, and the design of the building. Can you guess what it is?

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ketika kamu mau masuk kedalam ruangan baik rumah,kantor,sekolah. kamu pasti melewatinya. Tingginya berbeda-beda satu dengan yang lainnya, ada yang 2 meter,3 meter,bahkankan lebih karena disesuaikan dengan kondisi tempat,bentuk,dan disain bangunannya. Bisakah kamu tebak apakah itu?

*Thanks*