A. imperceptible B. how-to C. story D. graceful A. space flight B. rickets C. about D. ha A. adapt to B. group C. Sahara D. height A. won B. a lot of C. waterlogged D. war A. meow B. incur C. look out D. out of date A. pale B. owe C. keep on D. watch films A. run B. dance C. eve of the Spring Festival D. staff A. with B. physiological C. methane D. stage A. go to a summer camp B. silt C. parden D. wet A. album B. read C. extraordinary D. fee