dieu che butadien-1,3 tu etanol ngoai ra con co hai san pham phu la XYma tu Y dieu che duoc X viet phuong trinh phan ung hoa hoc xay ra. xuc tac Mgo, SiO2 dun nong 270-390oC ccd

dieu che butadien -1,3 xuc tac MgO,SiO2 tu etanol ra hai san pham phu YX tu Y dieu che duoc X viet phuong trinh hoa hoc xay ra ccd

The state of Michigan has endowed three institutes to ______ research for industry.
A. act B. do C. order D. list

Science and technology (S&T) capabilities are fundamental for social and economic
progress in developing countries; for example, in the health (19) ______ , scientific research
led to the development and introduction of oral rehydration therapy, which became the
cornerstone of international (20) ______ to control diarrheal diseases. Research also
established that two cents worth of vitamin A given to children every six months could (21)
______ child mortality in many countries by over one-third. In agriculture, rice-wheat rotation
techniques have significantly enhanced food production in South Asia. In Central America,
scientifically based natural resource management has been essential in developing the
tourist (22) ______ , a major source of foreign currency.
International programs based on S&T are critical components of U.S. foreign policy, and
particularly foreign assistance activities. Foreign assistance, probably more than any other
international endeavor, (23) ______ opportunities for representatives of the U.S. government
and its partners to join with political and economic leaders, intellectuals, and activists of
dozens of countries in continuing, constructive dialogues and in concrete projects designed
to enhance the quality of life of hundreds of millions of people. S&T are often the keystones
for (24) ______ projects. The shared political and economic dividends from these activities
can be enormous.

19. A. sector B. area C. region D. item
20. A. nations B. sessions C. owners D. efforts
21. A. mention B. reduce C. survey D. conflict
22. A. career B. branch C. industry D. agriculture
23. A. surround B. provides C. combines D. impresses
24. A. friendly B. beautiful C. delicate D. successful

giải thích nữa nha mọi người ơi.

1. __________ the tornado hit, there was very little left standing.
A. Despite B. Although C. Before D. After

3. ______ housing isn’t enough – we also need job opportunities.
A. Exciting B. Affordable C. Immediate D. Technical

III. Read the following passage. Decide if the statements from 13 to 16 are True or
False, and choose the correct answers (A, B, C or D) for questions 17 and 18. (1.5 pts)
Plastics is the term commonly used to describe a wide range of synthetic or semi-
synthetic materials that are used in a huge and growing range of applications. Everywhere
you look, you will find plastics. We use plastic products to help make our lives cleaner,
easier, safer and more enjoyable. We find plastics in the clothes we wear, the houses we live
in, and the cars we travel in. The toys we play with, the televisions we watch, the computers
we use and the DVDs we watch all contain plastics.
Plastics are organic materials, just like wood, paper or wool. The raw materials used to
produce plastics are natural products such as cellulose, coal, natural gas, salt and, of course,
crude oil. Plastics have become the modern material of choice because they make it possible
to balance today’s needs with environmental concerns.
The term “plastic” is derived from the Greek word “plastikos”, meaning fit for moulding.
This refers to the material’s malleability, or plasticity during manufacture, which allows it to be
cast, pressed, or extruded into a variety of shapes - such as films, fibres, plates, tubes,
bottles, boxes, and much more.

(Adapted from https://www.plasticseurope.org)

13. Plastics is the term describing a wide range of synthetic materials only.
14. We find plastics everywhere except the clothes we wear.
15. Cellulose, coal, natural gas, salt and crude oil can be used to produce plastics.
16. The word “plastic” in English has its origin in Greek.
17. What is the passage mainly about?
A. Synthetic or semi-synthetic materials
B. Plastic products in everyday life
C. General understanding of plastics
D. Raw materials used to produce plastics
18. What allows plastic to be cast, pressed, or extruded into a variety of shapes?
A. Its high boiling point B. Its toughness
C. Its cellulose origin D. Its malleability

Mấy câu này giải thích cựn cẽ giups mình nha không hiểu lắm.Làm ơn.

Cho một quần xã sinh vật gồm các laoif như sau: chim sâu, thực vật, bọ ngựa, cầy, sâu, chuột, hươu, hổ , vi sinh vật. Em hãy vẽ một lưới thức ăn.

Nhanh nha mai thi rồi thanhks chúc mn thi tốt. dhn

Có 5 lọ hóa hấ khác nhau mỗi lọ cghwas mộ rong các hóa chấ sau:C6H12O6, C2H5OH Al2(SO4)3 NaOH HCl. Không dùng hêm huốc huer hử khác hã phân biệ các dung dịch đựng rong mỗi lọ.

nhanh nha mình gấp lắm rồi

Hòa tan hoàn toàn a gam kim loại M trong dung dịch HCl dư, thu được dung dịch S và 2,24 lit H2(đktc).Chia A thành 2 phần bằng nhau:

- Phần thứ nhất tác dụng hoàn toàn với KOH dư, thu được kết tủa B. Nung B trong không kgi ở nhiệt độ cao tới khối lượng không đổi, thu đc (b+2,4) gam chất rắn C.Hoa tan C ỷong H2SO4 loãng dư đc dung dịch D. XỬ LÍ PHQN THỨ HAI CHỈ THU ĐC MỘT MUỐI Y DUY NHẤT VỚI KHỐI LTƠNG 19,9 GAM XÁC ĐỊNH CÔNG THỨC CỦA MUỐI Y X BIẾT A=2B GIẢI THÍCH CHI TIẾT CHO MÌNH PHẦN TỈ SỐ VỀ HÓA Ỷ NHA.