Change the voice in the sentences given below by selecting the correct alternative: 

Many serious accidents are caused by negligence. 

Change the voice in the sentences given below by selecting the correct alternative: 

They have proved all his calculations wrong. 

Change the voice in the sentences given below by selecting the correct alternative: 

Somebody has already used this towel. 

Change the voice in the sentences given below by selecting the correct alternative: 

We had to count the money. 

Change the sentences as directed, choosing from the options given below

He kept looking at her, wondering where he ______ her before. 

Fill in the blanks with the correct tense of the verb from the given options: 

It rained so hard that we_____ not go out.

Fill in the blanks with the correct tense of the verb from the given options: 

I was sure that he____ succeed.

Fill in the blanks with the correct tense of the verb from the given options: 

She broke down when she_____ the news.