______ in the woods, the cottage was a good shelter from the enemies.

Compared with her sisiter, Jerry is even more _______ to, and more easily troubled by, emotional and relationship problems.

In order to be a strong and effective partner with the Asia Pacific region, American president Obama thinks it absolutely      to have a strong relationship with China．

Sex education is a sensitive area for some parents, and thus it should remain _________.

 When it comes to the civil war in Syria, the US government’s attitude towards it has experienced a(n)_______ change , which may have a positive effect on Syria present situation.