Objective: To evaluation the feasibility of a new approach to positioning of a left-sided double-lumen endobronchial tube properly: under the premise of the tube size matches for the left mainstem bronchial diameter ,withdrawing the tube after it was inserted into the left bronchus and the resistance was felt, positioning the tube correctly without the aid of any instrument.

However in the link of last effort,the left support technique has the direct influenec on the effect of passing power and making power.

Analysis of the left-supporting skill in the final put in shot put;

Major skills in shot sport are holding,sliding,pushing with force at last and keeping body s balance after finishing the whole action,among which pushing with force at last is the key that will determine the athlete s score; however,left-supporting plays an important role in the process.