渐变映射命令实质上是首先将图像转化为黑白图像，然后使用渐变映射在上面。
查看答案
“图像/调整/可选颜色”命令选择某种颜色范围进行针对性的修改，在不影响其他原色的情况下修改图像中的某种原色的数量。
A. 对
B. 错
How would the bill be paid?
A. By credit card.
By business card.
C. By debit card.
What document is needed for the check-in?
A. ID card
B. Passport
C. Business card
What is the room number?
A. 6030
B. 1613
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