宣于

1

宣之于口是口头作文，笔之于书是书面作文。

Speaking it out is oral composition , and writing it on the paper is written composition .
2

是非分明的答案或许在宣之于众时听起来很动人，但实际操作起来它们很难成为最佳策略。

Neat answers might sound impressive in a presentation , but they are rarely the best policy on the ground .
3

事实上，这种难以宣之于口的紧张是由于更深层次的变化所导致的：中国将利用这个新银行扩大其影响力；而亚洲的现有势力，美国和日本，则会此消彼长。

But the real , unstated tension stems from a deeper shift : China will use the new bank to expand its influence at the expense of America and Japan , Asia 's established powers .