There are more than fifty ________ in our school.

Scientists have to work hard to keep ________ with modern discoveries and developments..

---What do you think of the project put forward by the Blacks? --- Considering its real _______, it will be well worth putting into practice, I suppose.

. School children must be taught how to deal with dangerous ________.

They put_______on the government to lower taxes and give laid-off workers necessary health care.