Tỉ khối hơi của anđehit X đối với không khí bằng 2. Tên của X là:

Chia sẻ

Một số câu hỏi khác có thể bạn quan tâm.

• Sản xuất của cải vật chất là quá trình
  
• Read the passage carefully and choose the correct answers
  Marriage nowadays is a choice people make on their own, but this has not always been the case in society. Thousands of years ago, the average lifespan was shorter than it is today. A man usually lived until he was about 40 years old, while women died even sooner because of childbirth. There were many wars and illnesses, and people had to protect themselves by having more children while they were still young. The parents lived through their children.
  Marriage was not so much a romantic love story but a business transaction, or deal. Most marriages were arranged between parents while their children were still very young. It was the custom that the fathers made the decision on whom their children were going to marry. The mothers had little say in it since they rarely made any decisions outside the household. The fathers would meet to arrange the wedding date and the money given for the bride on her wedding date. The more money and land a girl had, the more chances she had to marry well. Therefore, it was important that her father choose the bridegroom very well. Usually, it was someone who came from a good family or who was rich too. It was very unlikely that people married outside their social class. A few well-off and rich merchants got to marry poorer noblewomen and became King’s business advisors. In a way, poor peasants had an easier choice as it was less important whom they married.
  The practice of arranged marriage is still common in some countries in the Middle East, such as India or Pakistan. Here, social classes are still strongly divided and very well-kept. Often, however, arranged marriages are a sign that people do not want to let go of the past, which gives them comfort and security in an ever-changing world.
  (Adapted from Longman Essence Reading, Vol. 2)
  Question . The phrase "let go of" in paragraph 3 mostly means ______.
  

• Cho hàm số có bảng biến thiên như hình vẽ bên dưới   Hỏi hàm số có bao nhiêu điểm cực trị ?

• Phương trình có tập nghiệm trùng với nghiệm của phương trình nào sau đây?                         

• Từ một hộp chứa quả cầu màu đỏ và quả cầu màu xanh, lấy ngẫu nhiên đồng thờiquả cầu. Xác suất để lấy được quả cầu màu xanh bằng

• Cho bảng số liệu:
  SẢN LƯỢNG LƯƠNG THỰC VÀ SỐ DÂN CỦA MỘT SỐ NƯỚC TRÊN THẾ GIỚI NĂM 2014.
  
  Nhận xét nào đúng từ bảng số liệu trên ?

• Nhà Nhà Hán chia nước ta thành mấy quận để sát nhập vào bộ Giao chỉ?
  
• Câu “Một cây làm chẳng nên non, ba cây chụm lại nên hòn núi cao” là thể hiện ?
  

• Cách hiểu nào dưới đây về mối quan hệ giữa sự biến đổi về lượng và sự biến đổi về chất là đúng?

• That is ________most beautiful beach in Vietnam that I’ve been to.