I like getting up very early in summer. The morning air is so good ______.
The flu is believed _____by viruses that like to reproduce in the cells inside the human nose and throat.
The flowers _________sweet in the botanic garden attract the visitors to the beauty of nature.
--You have made progress in your English study, haven’t you? --Yes, but much ____. A remains to do B is remained to do C remains to be done D is remained to be done
The boy ________ in the bed ________ to his friend that a cock laid an egg yesterday.
This book ______ 50 maps, _______ 20 of America’s.