Thứ Ba, 5 tháng 11, 2013

Construction Safety

http://www.youtube.com/v/gzcwhEQ4xjA?version=3&autohide=1&showinfo=1&autohide=1&autoplay=1&feature=share&attribution_tag=eNnPeEGuSbSUd1iEneewHg

Bridge Construction Safety

http://www.youtube.com/v/4s6BY15Wu9w?autohide=1&version=3&autoplay=1&showinfo=1&attribution_tag=gdxoOuq0s1XZQTRWo1HvtQ&autohide=1&feature=share