Voluntary attention refers to the attention with a predetermined purpose and requires a certain will effort: non random attention refers to the attention without a predetermined purpose and no will effort in advance; Random attention occurs after random attention. It has a certain purpose and task, and does not need the attention of will and effort.
According to the above definition, which of the followings is voluntary attention
When Xiao Lin was reading in front of the window, he suddenly heard some noise outside. He looked up and found two birds parked in the tree