Troop Strength InViet Drops By 800SAIGON (AP) The U.S.Command announced today a drop in American troop strength in Vietnam last week of 800 men, lowering the total to335,000.The command also announced that the 3rd Squadron of the 11th Armored Cavalry Regiment was withdrawn from combat status today preparatory to redeployment. This will reduce troop strength by 1,140 men in the near future.The total strength is scheduled to drop to 284.000 men by May 1, and President Nixon has said he will announce additional withdrawals in April.Ninth graders of 1959 were as mature as 12th graders of 1938, according to a study reported in Encyclopaedia Britannica.