18. I am not sure whether I can gain any profit from the investment, so I can’t make a(n) ____ promise to help you.
A. exact B. defined C. definite D. sure
investment 投資
investigate 調(diào)查
irrigate 灌溉
irritable 激怒的
navigate 航行
castigate 懲罰
mitigate 緩和，調(diào)解，減輕
sure 確信
insure 保險(xiǎn)
ensure 確保
define 限定，下定義
final 結(jié)束的
refine 提純
finance 財(cái)政，資金
