7.挑战n./向…挑战 v._________ 8.怀疑v./嫌疑犯n. _________ 9.宣布；通告 v._________ n. _________ 10.建设 v._________ n.建筑物_________ 11.贡献；捐助v.________ n.________ 12.拒绝v.________ n. ________ 13.污染v.________ n. ________ 14.谨慎的________ n.小心；警告________ 15. 热情的________ n.________

challenge

suspect

pollute

pollution

announce

announcement

construct

[sə'spekt] / ['sʌspekt]

construction

contribute

contribution

reject

rejection

enthusiastic

enthusiasm

cautious

caution