help的形容詞形式和反義詞是？

It is often helpful for teachers to shadow managers in industry.

教師跟隨業界的管理人員實地學習，常常會很有收穫。

I called the police but they weren't very helpful.

我叫了警察，但他們不太肯幫忙。

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

把情況和朋友詳細聊一聊，你會覺得大有幫助。

The waiters were rude and unhelpful, the manager ditto.

這些服務員態度生硬，服務不周，經理也一樣。

It is unhelpful to extrapolate general trends from one case.

根據一個案例來推斷總的趨勢是沒有用的。

People always complain that the big banks and big companies are unfriendly and unhelpful

人們總是抱怨大銀行和大公司不友善、不願提供幫助。