You made the same mistake for _____ second time, dropping _____ “n” in the word “government”.
| A．a; the | B．a; a | C．the; an | D．a; an |
There is a natural phenomenon scientists call the greenhouse effect.
| A．that | B．what | C．for which | D．who |
Every time I returned after an , I felt stupid because I was behind the others.
| A．ambition | B．abandon | C．absence | D．appoint |
However, the eruption itself is really exciting and I shall never forget my first sight of one.
| A．to watch | B．to be watched | C．watched | D．watching |
I go back to sleep when suddenly my bedroom became as bright as day.
| A．was about to | B．was just to | C．would | D．was to |
It is human activity has caused this global warming.
| A．which | B．that | C．what | D．why |