Open the brackets using Present Simple, Present Continuous, Past Simple or Past Continuous. Write down full sentences. My flatmate (always/leave) the bathroom in a mess!
I'll call you when I (to get) home.
The coffee (to taste) really bitter.
Kathy (to fall) off the ladder when she (paint) the wall.
While we (to have) tea, it (to start) to rain.
Mark (live) in Prague for a few months (usually he lives in London).
When we (to decorate) a Christmas Tree, Santa Claus (to come).
(you/to start) to work at school in 2001?
I (to drink) coffee every morning.
The next train (to leave) this evening at 17.00.

My flatmate always leaves the bathroom in a mess!

I will call you when I get home.

The coffee tastes really bitter.

Kathy fell off the ladder when she was painting the wall.

While we were having tea, it started to rain.

Mark is living in Prague for a few months, but usually, she lives in London.

When we were decorating a Christmas Tree, Santa Claus had come.

Did you start to work at school in 2001?

I drink coffee every morning.

The next train is leaving this evening at 17:00.

Explanation:

Simple present or present indefinite tense is employed to denote universal truths, habitual/regular actions, and the present actions. It is formed using 'sub + V1 + s/es with 3rd person singular.' While present continuous tense is employed to denote the ongoing action in the present and formed by using 'sub + is/am/are + V1 + ing.' Past simple tense is used to describe the completed actions or past events that took place at a specific point of time in the past and thus, it uses 'sub + V2.' Past continuous tense is used to denote the actions that began at particular point of time in the past and were in continuity in the past. It uses 'sub + was/were + V1 + ing.' These tenses have correctly been employed to fill the above sentences.

the answer is b. my dude

your answer is c) experiments with water vapor showed that elements combine in specific proportions.