The sentences given with blanks are to be filled with an appropriate word(s). Four alternatives are suggested for each question. For each question, choose the correct alternative and click the button corresponding to it.
The train is expected to arrive in a few minutes _____ platform six.
When iron is exposed to moist air, a reddish brown coating of hydrated Iron (III) Oxide (Fe2O3) is deposited on its surface. This reddish brown coating is called