Putting an index finger up to the lips is a popular way _____ Be _英语解答

Putting an index finger up to the lips is a popular way _____ Be quiet
to say
for saying
of saying
of say

人气：129 ℃　时间：2020-04-13 04:50:18

解答

Putting a index finger up to the lips is a popular way to say Be quiet.
其实就是省略了不定代词的句子