expect命令问题1

[root@localhost scripts]# cat exptest.sh
#!/usr/bin/expect
spawn ssh root@127.0.0.1
expect "password: "
send "oracle
"
sleep 1
send "ls
"
#send "ls >/tmp/l3.log
"
send "echo status:$?
"
expect -re "status:([0-9]+)" { exit $expect_out(1,string) }
exit
send "ls
"
interact

关键字sleep 1，不加的话后面的命令都不会执行，很纳闷