In this world there is no shortcut to take.So people, no matter how clever they are, can’t succeed_______ they work hard.

Mary won’t keep slim ______she takes exercise every day.

Today is Wednesday. He _______ be at home. He _____ be at school.

Don’t ________the light, I _______ a report.

比较下列加横线词的意义和用法，判断正确的一项是（ ） ①奉宣室以何年 ②处涸辙以犹欢 ③臣死且不避 ④穷且益坚