Food safety is very important. -So some rules to stop people from polluting food.

Last week, our class did on our school trip.

ular attention must be paid ______ welfare,especially in the poor area.

It is reported that the government has ______ the poor in some African countries ______ food, clothes and medicine.

In making a scientific experiment, one should not be _____ by temporary setbacks but should stick to doing it hopefully.