shell脚本数组报错Syntax error: "(" unexpected-centos易出现问

cat 3.sh
#!/bin/sh
a=( 1 2 3)
for number in ${a[@]}
do
echo $number
done

执行命令
sh 3.sh
3.sh: 2: 3.sh: Syntax error: "(" unexpected
执行该脚本，在有的机器上会报错Syntax error: "(" unexpected

bash 3.sh
1
2
3
与你实际使用的shell版本有关。你可以用 ls -l /bin/*sh 打印出来，例如：
ls -l /bin/*sh
-rwxr-xr-x 1 root root 1021112 Oct  7  2014 /bin/bash
-rwxr-xr-x 1 root root  121272 Feb 19  2014 /bin/dash
lrwxrwxrwx 1 root root       4 Dec  4 01:40 /bin/rbash -> bash
lrwxrwxrwx 1 root root       4 Dec  4 01:40 /bin/sh -> dash
lrwxrwxrwx 1 root root       7 Nov 14  2013 /bin/static-sh -> busybox