老师告诉小明，如果他能按时完成作业就不会受批评，小明决定以后每天都要按时完成作业。这种心理学现象是（ ）。

(单选题)From Paragraph 1, which of the following is NOT true? (单选题)If you buy four books (one for each), how much can you save? (单选题)You read this advertisement most probably ______. (单选题)Which book is the most popular one among the buyers? (单选题)30.（ ） (单选题)29.（ ） (单选题)28.（ ） (单选题)27.（ ） (单选题)26.（ ） (单选题)25.（ ）