填空题
Complete the summary below.
Write NO MORE THAN TWO WORDS for each answer.
Production of Rice
Rice gives more
____5____
per hectare than other cereal crops and production has increased over 100% in recent years because of better yields. Land area has only increased by 30% due to the need for wet land so availability of land is quite limited by
____6____
type and
____7____
supply. The dry-land variety gives poorer yields and poorer
____8____
No weed killers have been developed yet that do not harm the main crop. Heavy machines are unable to work in paddy fields so most rice is still grown
____9____
.