A. do some research B. welcome C. let D. appendicitis A. clothes B. medical C. dirty D. concrete A. pick B. huge C. cosmonaut D. science fiction A. baleen whale B. have to C. lift up D. at the foot of A. put out B. have a fever C. before D. lifeboat A. understand B. family tree C. swell D. trend A. why B. ago C. jewel D. fruit A. mushroom B. necessary C. angry D. upside down A. digestive B. that's all C. because D. mattress A. take off B. spacecraft C. confusing D. June