A. float B. wisdom C. arrive in D. biology A. clean-up B. knock on C. lessen D. the poor A. swim B. satellite C. investigation D. narrow A. thankfully B. biologist C. half D. court A. key B. glance through C. physicist D. cut short A. then B. thus C. process D. kidnapping A. lay eggs B. anymore C. take off D. apartment A. go back B. programme C. together D. billion A. Big Ben B. cash crop C. atmosphere D. have a party A. exist B. twin towers C. breakfast D. receive