Which substance is used to enhance x-ray and CT

"The scientist’s groundbreaking research on renewable energy sources was hailed as a major _______ in the field of environmental science."

Bhanu made a working model of an airplane ______ when he was sixteen.

The enactment of the Act was a legislative …... However, its implementation has been …………..

Sentences are given below with a blank. Fill in these blanks with the appropriate option.

The team decided to _______ after realizing their initial approach wasn’t working as planned.

Over time humanity has .............. ever greater ............. in controlling and commanding combustion – harnessing fire. 

Choose the correct alternative out of the four choices given below each sentence.

I correspond _____ her regularly

Choose the correct structure to complete the sentence.

Sanjay has been posted in Hyderabad, _________ birthplace.

Select the most appropriate option to fill in the blank.