预约成功
effective
名词: effectiveness
adj.有效的;生效的;实际的
例句：用作形容词 (adj.)
Advertising is often the most effective method of promotion.
做广告往往是最有效的推销方法。
When does the new system become effective?
新制度何时生效?
Her brother is the king, but she is the effective ruler.
她的兄弟是国王, 但她才是实际的主宰者。
Last year saw a decline in the effective demand for steel.
去年,钢铁的实际需求下降了。
