1. You will not improve your skill in a short time you practise playing the violin regularly.
2. you don't work hard, you will fail the exam.
3. Tom can't be here on time he gets up early.
4. you don't have enough sleep, you will feel tired.
5. you finish your homework, you can't go out to play.

1. unless 2. If 3. unless 4. If 5. Unless

1. If Amy takes part in the game show, she (win) a prize.
2. Unless you try your best, you (not realize) your dream.
3. Everybody (be) sad if we don't win the football match.
4. If you (not keep) the meat in the fridge, it will go bad.
5. Unless I (invite), I won't go to the party.
6. (2023·江苏无锡)If this (go) on, the wild animals will soon have nowhere to live.

1. will win 2. won't realize 3. will be 4. don't keep 5. am invited 6. goes

()1.(2023·湖南岳阳)You won't pass the PE exam successfully ______ you exercise every day.
A.if
B.unless
C.as long as
D.since

B 【点拨】if 如果；unless 除非，如果不，相当于 if... not；as long as 只要；since 由于。根据语境可知，后句是前句的否定条件，应用 unless 引导条件状语从句。故选 B。

()2.(2023·安徽)Our country will be much better for everyone ______ we all do something to help now.
A.if
B.before
C.so that
D.even though

A 【点拨】if 如果，引导条件状语从句；before 在……之前，引导时间状语从句；so that 为了，引导目的状语从句；even though 即使，引导让步状语从句。由句意可知，本句用 if 引导条件状语从句。故选 A。

()3.(2023·黑龙江绥化)I don't know if it ______ sunny tomorrow. If it ______ sunny, I will go fishing.
A.will be; is
B.is; will be
C.will be; is going to be
D.will be; will be

A 【点拨】前句是 if 引导的宾语从句，主句是一般现在时，根据 tomorrow 可知宾语从句用一般将来时，排除 B；后句是 if 引导的条件状语从句，遵循“主将从现”原则，从句用一般现在时，排除 C 和 D。故选 A。

()4.—You are not supposed to enter the teachers' office ______.
—Thanks, Mum. I got it.
A.unless you are allowed to
B.if you want to ask questions
C.when you are asked to come in
D.where you are going

A 【点拨】A 项意为“除非你被允许”；B 项意为“如果你想问问题”；C 项意为“当你被要求进入的时候”；D 项意为“你将要去哪里”。故选 A。