The water of a hot spring carries many minerals,usually _________ us an unusual taste and smell.
| A．has given | B．gives | C．to give | D．giving |
.He walked down the hills, _______ softly to himself.
| A．sing | B．singing | C．sung | D．to sing |
.At this moment the bell rang _______ the end of class.
| A．announce | B．announcing | C．announced | D．to announce |
The child sat in the dentist's chair _______.
| A．tremble | B．trembling | C．trembled | D．to trembled |
Properly _______ with numbers, the books can be easily found.
| A．marked | B．mark | C．to mark | D．marking |
Were you _______ when you saw that wild animal?
| A．fright | B．frightening | C．frightened | D．frighten |