During the discussion, I ________(鼓起)my courage to ask a puzzling question．

The teacher's words ________(对起作用)him, and he realized he had made a mistake．

根据句子的意思，用work up的适当形式填空。

He tried to ________ the enthusiasm of the crowd．

根据句子的意思，用work up的适当形式填空。

Tom couldn't ________ the courage to jump off the high rock and into the lake．

根据句子的意思，用pull in的适当形式填空。

The diet industry is extremely profitable ________ 33 billion each year．

根据句子的意思，用let on的适当形式填空。

If he ever noticed or was bothered, he never ________．

根据句子的意思，用let on的适当形式填空。

Don't ________ that you know me．

根据句子的意思，用let on的适当形式填空。

You will have to apologize to me for ________ the business secret．

根据句子的意思，用engage的适当形式填空。

Unable to ________ many activities, my father still tried to participate in some way．

根据句子的意思，用adjust的适当形式完成句子。

He ________ himself very quickly ________ the heat of the country．