bill must study hard.otherwise he will fail in the examination.将简单句连接成带状语从句的主从复合句

Bill must study hard in case he will fail in the examination.
比尔必须努力学习以免考试不及格。

Bill will fail in the examination unless he studies hard.

Bill will fail in the examination unless he studies hard.
If Bill doesn't work hard,he will fail in the examination.