题目内容：

It's said that the police ___ (try)their best to find the missing travelers these days.
We ___ (organize) a school trip to the park unless it rains this Saturday.

优质解答

if (mysqli_connect_errno())
{
echo 'Error:Could not connect to database.Please try again later.';
exit;
}
这个是检查PHP是否连接上MYSQL,就是一个判断函数