A. catch up with B. opera house C. go home D. road A. be heavy with B. safe C. pine D. passenger A. let's B. sports meet C. milometer D. silk A. Santa Claus B. along C. is D. zoology A. trip B. noodles C. robber D. Tian'anmen Square A. worker B. dish C. rare D. went camping A. leave behind B. ecology C. graduate D. tour A. firmly B. estimate C. difficulty D. main A. date B. enjoy C. have classes D. floor A. sweat B. counteract C. Terra Cotta Warrior D. alarm