A number of students____  attending the meeting now and the number of students _____more than 100.

—Does the old man know the museum very well? —No, this is the first time he __________ here.

Either you or one of your students________ to attend the meeting that is due tomorrow.

------ Why does the lake smell terrible? ------ Because large quantities of water _________.

There is _____　a pen, an eraser and some pencils in her pencil-box.