Dhruv: let us go for a movie, madhav. madhav: i am sorry, i (can, must not cannot). i (shall, must, need) to reach home immediately. dhruv: but why (could, would, should) you be in such a hurry? madhav: my mother is ill. i (would, must, need) take her to the hospital immediately. dad is out of town.

Dhruv: Let is go for a movie, Madhav.

Madhav: I am sorry, I CANNOT (because this word indicates that Madhav is not able to go). I NEED (because this word means that he has to do something, and it’s the only word that can fit before ‘to’) to reach home immediately.

Dhruv: But why SHOULD (it is a polite word to use when asking someone why they are doing something) you be in such a hurry?

Madhav: My mother is ill. I MUST (this word also means ‘need to’, but there is no ‘to’ after the blank word so this is the only one which makes sense) take her to the hospital immediately. Dad is out of town.

uncanny would be like unlucky or disaster. you can look for more in the dictionary or if you have text book then turn to a. 17 but it's different with textbooks.