The booklet should be very helpful to parents of disabled children.

这本小册子对于残疾儿童的父母会很有用。

Who is helpful to her?

谁可以帮助她呢？

It is helpful to use well-known ideas such as an ambulance siren or a gunshot because these sounds carry a lot of context with them.

使用诸如救护车汽笛或枪身之类众所周知的音效是有帮助的，因为这些声音本身蕴含了环境信息。

You'll find it helpful to talk things over with a friend.

把情况和朋友详细聊一聊，你会觉得大有帮助。

When you go to concerts, it's helpful to read the programme.

去音乐会的时候，看看节目单是有帮助的。