让受试者直接用数字表示心理强弱，测量广告心理效果的一种方法是（）
A.数量估计法
B.对偶比较法
C.等级量表法
D.多级估量法
参考答案：A
_______ for months to find a job as a cartoon maker, John finally took a position at a local advertising
agency. [ ]
A. Struggling
B. Struggled
C. To struggle
D. Having struggled
李叔叔每小时加工a个玩具，8小时可以加工______个．
