阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。
    Have you ever tried to hide your feelings from someone during conversation？It's not always easy，as the color of your face might tell （1）

the

the

truth.
    Scientists from Ohio State University have found that people can tell other people's feelings according （2）

to

to

changes in the color of their faces.They （3）

carefully

carefully

（careful） studied pictures of people's facial expressions and found that every facial expression has a special color pattern.For example，happiness （4）

makes

makes

（make） our cheeks （面颊） red.Dislike creates a blue-yellow color around the lips （嘴唇） and a red-green color around the nose.
    "We believe these color patterns（5）

are caused

are caused

（cause） by small changes in blood flow （流量），" lead researcher Aleix Martinez said.
    But this raises（6）

questions

questions

（question）：Is it the color alone that helps people tell others' feelings？Aren't facial expressions useful？
    To work（7）

them

them

（they） out，scientists added color patterns to pictures of faces that showed no facial expressions.They asked volunteers to tell what feelings the faces were showing.Volunteers were able（8）

to give

to give

（give） correct answers 75 percent of the time.
    This might explain（9）

why

why

there are some sayings that connect feelings to the color of one's face.For example，when two people are arguing over something heatedly，we say they are "red in the face".When a person is rather （10）

scared

scared

（scare），we'd say his or her face is "white as a ghost".