a. Khi sôi thì nước sẽ bị bốc hơi, nhưng do đậy vung nên hơi nước không thoát ra ngoài được  hơi nước tụ lại thành nhiều giọt nước trên nắp vung.

b. Có vị giống nước bình thường. Nước trong nước muối đã bay hơi.

Dứa là loại cây bụi mọc sát mặt đất, vỏ lại xù xì nên quả là nơi cư trú của nấm. Khi dứa bị dập nát, dịch bào thấm ra, nấm sẽ phát triển, xâm nhập sâu vào trong quả, gây ngộ độc cho người ăn. Các triệu chứng ngộ độc thường thấy là mệt mỏi, khó chịu, ngứa ngáy, nổi mề đay.

Mưa nhân tạo được tạo ra bằng cách cho một lượng  cacbon dioxide nho nhỏ vào các đám mây. Đương nhiên muốn có mưa phải có mây, ta có thể tạo mây nhân tạo

Education is very important in modern world for both males and females and every boy and girl need to get a quality education. In some nations, younger and teenagers get education in separate schools while other countries prefer co-education. In this essay we will discuss advantages and disadvantages of separate and co-education of both genders.

First of all, in teenagers there were many problems which the elders need to control and have proper check on them. Education plays a great role in the mind and character building of both male and females. Those nations, which provide separate education for boys and girls, have the opportunity to maintain disciplines in both boys and girls, and most of the time they will give a better result to the society.

Secondly, separate education gives opportunity to those students especially girls in many countries, who didn’t want to study in co-education, and they get their required education from those schools in which separate educations are available.

However, there are still some drawbacks of separate educations as well. For example, in co-education both boys and girls earn a lot of confidence, enable them to deal with opposite genders, and they face no problems in their professional life.

All in all, separate education has some advantages on boys and girls and on the society as well but still it has some disadvantages and some countries provide to co-education to facilitate their generation with modern awareness.