First, read the English article below.

You can either simply set it on a table, counter, any other completely flat surface, or attach it to a tripod using rubber bands or tape. Because of the sensitivity of the shutter, you need the camera to be extremely still as you take photos. For film, you only need to expose the camera to light for a few seconds, but photographic film can take up to a few minutes.  If using film, the duration of exposure depends on the ISO of the film. The higher the ISO, the shorter the exposure time. For 400 ISO film, you will expose it to light for between 2 and 12 seconds depending on the brightness of the external light. For 100 ISO film, the exposure time can range between 8 and 48 seconds, and for 50 ISO film, the exposure time may range between 16 seconds and 1 minute and 36 seconds.  If using photographic paper, the exposure time will most likely range from one minute to several minutes, though there are photo paper products made specifically for longer exposures, even up to several months! You will have to practice to determine the exposure time that works for you, but remember the general rule of thumb for exposure time: the brighter the external light, the shorter the exposure time. Remember to account for the distance between the pinhole and the viewfinder by aiming a bit lower than you might perceive. 

Now, please write a short abstract for it in Chinese. Abstract:
把相机放在平坦的表面上。 确定曝光时间。 对准要拍摄的物体。