The world’s population is getting larger and larger, so scientists are trying to _______ new ways to solve the food problem.
The children left without ________ “Goodbye”.
Do children_______on that day?
Children play"_______" on the people at Halloween.
The cartoon is really _________, so most of the children are ________ in it.
---Is it time for us lunch?----No , it’s only ten o’clock.