Comparing

The meaning is almost the same but slightly different. 際（さい） It is honorific. Strong purpose. (It usually means having a great opportunity.) Always used as Written language. (But it can be used in spoken Japanese.) It is a standard term usually used on business occasions and official documents. この 際 思い切って家族みんなでアメリカに引っ越しませんか。 In this case, " 際 " means opportunity. 時（とき） Always used as an Oral language. It is often used for things that happen by accident. 寝ている とき には地震があった。 You can't predict that an earthquake will happen. So, in this case, we use " とき "; Summary "...時"  usually means that other things happen in parallel or a specific state occurs at the same time ; In addition to the usage of  "...時" , the "...際"  is more solemn in tone than  "...時"  and has the meaning of "opportunity."

In fact, these three words are different, but there is no difference in daily conversation because they have the same pronunciation . Even the Japanese don't necessarily know these three words clearly, so most of them are written under hiragana instead. 1. おびやかす・おどかす・おどす  "おびやかす," which means threat and danger in an abstract sense. For example: endangering society, threatening the market, threatening the living environment, etc. "おどかす" means using What you said to make the others afraid , such as telling ghost stories to children, showing off their military strength to the other country, telling how severe the condition of the others is, and so on, which makes the others feel afraid. This is the purpose of "おどかす" This usage can also be replaced by "おどす", which expresses the same meaning. "おどす "means two things. One is a threat in a specific sense , that is, the threat of holding a knife and pointing at your nose . You can benefit

提示（ていじ）→show 提出（ていしゅつ）→submit 「書類を提示した。」Take back the documents right after you showed others. 「書類を提出した。」Submit the document to others. (Don't take it back.)

Words: さっぱり すっきり Similarities: Both of them have the same meaning.  "さっぱり" and "すっきり"? Both mean refreshing ,  neat , tidy, relaxed, cool, pleasant,  and so on . Differences: 1.  さっぱり 【さっぱり】 It is mainly used for cleaning and refreshing the body feeling ; 风吕に入って さっぱり した。  I felt excellent/ relaxed /pleasant/ cool  after taking a shower. ( body feeling ) 髪を切ったら さっぱり した  。  I feel good/excellent/ cool  after my haircut. ( body feeling ) 2.  すっきり 【すっきり】 It is mainly used for  mental feelings . 病気を治して すっきり した。 I feel good after being cured. (It's not body feeling.This feeling is like I feel relieved. I breathe a sigh of relief and become relaxed. ) 部屋の中も すっきりと 片づいた  。 The room was tidied up in a way that made me happy.  (I feel good,  psychologically.  The room may not be as neat or clean as you think, but I feel satisfied, comfortable, and relaxed. )