Choose the best answer.

Mary made a great contribution to her husband's success.

They are their children that most parents are willing to lend their ear to.

It is their children that most parents are willing to lend their ear to.

They are their children that most parents are willing to lend their ear.

It is their children that most parents are willing to lend their ear.

It is at the age of 20 that he gains impressive achievements.

It was at the age of 20 that he gains impressive achievements.

It is at the age of 20 that he gained impressive achievements.

It was at the age of 20 that he gained impressive achievements.

It is great enthusiasm that candidates all over the world took part in the competition.        

It was great enthusiasm that candidates all over the world took part in the competition.

It was with great enthusiasm that candidates all over the world took part in the competition.        

It is with great enthusiasm which candidates all over the world take part the competition.

It is in Da Lat that he spent his summer vacation.     

It was in Da Lat that he spent his summer vacation.

It is in Da Lat that he spends his summer vacation.

It was in Da Lat where he spends his summer vacation.

It is until the age of 15 that

It is not until the age of 15 that

It is the age of 15 that

It is until the age of 15 who

It is his girlfriend

It was his girlfriend's handbag

It is his girlfriend's handbag

It is his handbag