It 's harder than you might think .

这比你想象中的要难。

These questions are only going to get harder for mrs merkel .

这些问题对默克尔女士来说只会越来越难。

But sustaining the progress may become harder .

但要保持这种进步可能会变得越来越难。

Stiff blood vessels make your heart work harder .

血管硬化会使心脏工作更困难。

We need to work harder than men to prove ourselves .

我们需要比男人更加努力工作去证明我们自己。