the lekic competition field is a plan where the circuits that are made are presented to us by one person . the chemistry laboratory can do it by making the materials and make an experiment. we are currently making it. we will build a purposeful bridge that can carry 5 kilograms of concrete. each bridge must withstand 3 minutes , if the bridges that withstand it do not break, enter the competition. they enter the ranking again and the structure with the least weight is the winner. the national competition of student scientific research creativity is held every year among students regardless of age, and this december, the winners will participate in the oman world competition . hossein kashanian of radio and television news agency. 18 million cubic meters of water was stored in the back of nikshahr watershed structures. with more than 110 mm of rain recorded in this city, 375 stone dams mortar and soil have overflowed and 18 million cubic meters of water have been stored behind the dams. consequences of spring rains for drainage of watershed structures in nikshahr. recent rains in the city