`1.` Because of his carelessness, he made many mistakes

`->`  Because + S + be + adj → Because of + N

`-` careless (adj) → carelessness (n)

`2.` Despite the extremely cold weather, they continued their journey

`->`  Although + S + be + adj → Despite + N

 `-` the weather was extremely cold → the extremely cold weather

`3.` Because of not having enough money, she couldn't buy the laptop

 `->`  Because + S + V → Because of + V-ing

 `-` didn't have → not having

`4.` Although he lacked experience, he got the position

`->`  In spite of + N → Although + S + V

`-` his lack of experience → he lacked experience

`5.` Even though she felt exhausted, she kept working until midnight

 `->`  Despite + V-ing → Even though + S + V

`-` being exhausted → she was exhausted

`6.` Because of the road being under repair, traffic moved slowly

`->`  Because + S + be → Because of + N + V-ing

 `-` the road was under repair → the road being under repair

`7.` In spite of having prepared carefully, he didn't perform well

 `->`  Although + S + had + V3 → In spite of + having + V3

`-` had prepared → having prepared

`8.` Because she was determined, she achieved success

`->`  Because of + N → Because + S + be + adj

`-` her determination → she was determined

`9.` Despite receiving poor reviews, many people watched the film

`->`  Even though + S + V → Despite + V-ing

the film received → receiving

`10.` Because of living far from school, he gets up very early

`->`  Because + S + V → Because of + V-ing

 `-` he lives → living

`11.` Although she was injured, she finished the race

`->`  Despite the fact that + S + V → Although + S + V

`12.` Because prices increased, many people reduced their spending

`->`  Because of + N → Because + S + V

 `-` the increase in prices → prices increased

`13.` In spite of earning a lot of money, he is not satisfied

`->`  Although + S + V → In spite of + V-ing

 `-` he earns → earning

`14.` Because of her fluency in English, she got the scholarship

`->`  Because + S + V + adv → Because of + N

`-` spoke English fluently → her fluency in English

`15.` Although there was a risk, they decided to invest in the project

`->`  Despite + N → Although + S + V

`-` the risk → there was a risk