.
One advantage of eating a balanced breakfast is _____ it can keep you energetic throughout the day.
| A．that | B．how | C．when | D．whether |
________ in his book, he didn't notice me ________ I entered the room.
| A．Devoted; when | B．Absorbed; while |
| C．Absorbed; when | D．Devoted; while |
How can you expect him to make any progress ________ you never give him a chance to have a try?
| A．when | B．unless |
| C．even though | D．until |
I'm sorry you've been waiting so long，but it'll still be some time ________ Brian
gets back.
| A．before | B．since | C．till | D．after |
His mother likes to have him next to her ________ she can keep an eye on him.
| A．where | B．in which | C．there | D．when |
—You should have thanked the hostess before leaving.
—I meant ________.But I couldn't find her when I was leaving.
| A．to do | B．to | C．doing | D．doing so |