In that case, we must try hard.

这样的话，我们该努力些。

youdao

We must try hard attain this standard .

我们必须努力、达到这个标准。

youdao

So studying English needs patience. You must try your best to study the language no matter how hard it is. Don't give up, and we will succeed at last!

学习英语需要耐心，你必须尽你最大的努力，无论多困难都不要放弃，最后就一定会成功的，我们一起加油吧！

youdao

"We must keep working hard and go to Paraguay to try to win, " said Maradona.

CNN: Brazil win in Argentina to seal World Cup berth

And yet, no matter how hard it may be to start meaningful negotiations under current circumstances, we must acknowledge that a failure to try is not an option.

WHITEHOUSE: President Obama at 2011 AIPAC Policy Conference