Effects of Zinc on Photosynthesis and the Activities of Protective Enzymes of Chinese Cabbage in Calcareous Cinnamon Soil Effect of NaCl on Growth and Activities of Protective Enzymes in Seedlings of White Clovers(Trifolium repens L.) STUDIES ON THE ACTIVITIES OF ENZYMES OF PROTECTIVE SYSTEM DURING DIAPAUSE OF SAWFLY CHINOLYDA FLAGELLICORNIS