sentences:  On 15 January 1969 the 1st Marine Battalion joined Operation Goodwood with the 1st Australian Task Force replacing the 2nd Airborne Brigade.On 20 January they were replaced by Headquarters ARVN 52nd Regiment augmented by the ARVN 3/52nd Regiment and the 5th Marine Battalion.During Operation Lam Son 719 on 21 March 1971 the Marines at Fire Support Base Delta, south of Route 9 in Laos, came under intense ground and artillery attacks.