题目：What is the author’s position on subliminal projection in ads？A．He reveals none in the pas
What is the author’s position on subliminal projection in ads？
A．He reveals none in the passage.
B．He advocates its prohibition.
C．He considers it an exaggeration.
D．He acclaims its effectiveness.
此题为多项选择题。
题目问：作者对阈下投影的立场是怎样的?通过文章内容可知，作者没有对阈下投影提出自己的立场，整篇短文仅陈述事实及实践者、实验方、支持者及怀疑者的观点。所以，答案是A。