Polymerization process comprising the steps of: reacting an aqueous suspension comprising initiator, vinyl chloride, and optionally one or more co-monomers in a continuous stirred tank reactor; and further reacting the resulting suspension in at least one second reactor; wherein the conversion level of vinyl chloride in the continuous stirred tank reactor of step is from 10 to 60 wt %. The cleansing composition contains a plurality of thermochromic dyes that cause a color change to occur at a threshold temperature and continue to cause a color change over a temperature range. The MEMS chip is disposed over the surface of the substrate, including a second opening area and an upper electrode layer partially sealing the second opening area, wherein the upper electrode layer and the lower electrode layer, which are parallel to each other and have a gap therebetween, form an induction capacitor. , a MIRRORBIT two-bit EEPROM device or a floating gate flash device including a modified ONO structure. Accordingly, defective contact with the upper interconnection layer and the problems taking place in forming films can be prevented. The trimming apparatus include a cutter frame, a transmission belt, a motor, a clamping element, a switch and a mode-switching unit.