A. weak B. imperceptible C. youngster D. yak A. turbulent B. technical C. arrive at D. insurmountable A. walk into B. part with C. tangyuan D. explorer A. record B. thermodynamics C. sun cap D. dead A. telegram B. pole C. sculpture D. measure A. artificial B. uncomfortable C. ninepin D. lonely A. dry-clean B. have a party C. would like D. race A. diversity B. all day long C. unfair D. break the record A. thorough B. reproduce C. after-class D. go wrong A. nobody B. monstrous C. long jump D. hill