問題詳情：
從方框中選擇恰當的單詞完成句子
if， unless |
1．You can't improve your spoken English ______ you practice it every
day from now on.
2．There will be fewer cars in the city______ people choose the
subway.
3. Life is like a mirror. ______ you smile at it, it will smile back.
4. I will be very happy ______ you come to my party.
【回答】
1. unless 2. if 3. If 4. if
知識點：連詞
題型：完成句子
