What preposition can be inserted in the following sentence?

We've made some changes ... regard to the production process.

What verb can be inserted in the following sentence?

If you have any further questions, please do not ... to contact me.

What modal verb can be inserted in the following phrase so that it has the same meaning as in case you need it?

... you need it

Which closing expression is used when you don't know the name of the person you're writing to?

Which verb means to imagine or expect that something will happen, sometimes taking action in preparation for it?

Which preposition is missing in the following sentence?

There are some aspects that may be ... help, please read the following information.

Match the adverbs on the left with their synonyms on the right.