问题
选择题
--- This history book is of great value.
--- Exactly. ____________ can be enjoyed from it ____________ you have a deep understanding of it, however.
A．Nothing; unless
B．Few; till
C．Something; until
D．Little; since
答案
答案：A
题目分析：句意：--这本历史书很有价值。--的确如此。除非你对它有一个很深刻的理解，否则就不能很好的理解它。分析结合句意理解，只有运用连词unless适合。故选A
