Sentence Correction

16) Tom found the silver coin as he cleaning the floor.

1. as he cleans
2. as he cleaned
3. as he is cleaning
4. while cleaning

17) Jack unnecessarily picked up a fight with the bartender and left the party.

1. picking up
2. have picked
3. picked on
4. picked

18) Alice never have and ever will take such wrong measures.

1. has and never will take
2. had taken nor will ever take
3. had taken and never take
4. had and ever will take

19) Although he is a famous singer, yesterday performance was too disappointing.

1. yesterday performance was about
2. performance of yesterday were
3. yesterday's performance was
4. no correction required

20) One of the most important phenomenon of our times is the development of computer science.

1. of all phenomenon
2. phenomenas
3. no improvement required
4. phenomena