Identify the tense used in the following sentence:
I have been working on the problem.

From the options given below, select the most appropriate answer to fill in the blank in the given sentence.
I saw the man ________ from the first floor.

Complete the following conversation using the appropriate option:
A: What would you like to eat?
B: ________ a sandwich, please. (I/have)

A black cow that _______ in the field for some time did not return home in the evening.

Identify the tense used in the following sentence:
She has eaten her food.

To the astronomers of the Middle Ages, the most important classical authorities on natural philosophy _______ Aristotle and Ptolemy, since both _______ frameworks that explained the whole universe.

The Bastille Prison, where many important people _______ at one time imprisoned, _______ today visited by tourists.

Identify the tense used in the following sentence:
He has called out to him.

Choose the best form of the verb given in the bracket to complete the sentence:

When we heard the good news, we were _________. (delight)

Fill in the blank with the most appropriate option:

He met me with the bird in his hand. It _______ curiously at me.