THE MATRIX, the special effects driven science-fiction adventure, remained No. 1 at the US box office for the week ending April 11, with a weekend gross of $22.2 million, and a cumulative gross of $50 million. It slipped only 20% from last week. FORCES OF NATURE, with CGI effects by PDI, grossed $3.7 million; DOUG'S 1ST MOVIE fishished ninth, with $2.4 million, down 22% for a cum of $5.5 million; THE KING AND I finished 19th, with $571,625, down 44%, for a cum of $10.2 million; A BUG'S LIFE finished 22nd with a $400,809 gross, and a $161,946,399 cum; and PRINCE OF EGYPT finished 23rd, with $389,370 gross, and a cum of $100,240,570.