Mệnh đề chứa biến: “x³ – 3x² + 2x = 0” đúng với giá trị nào của x?

Thoát hơi nước có vai trò ra sao đối với cơ thể thực vật?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the best answer to each of the following questions from 31 to 40.

Biting into a ripe, juicy fruit brings a smile to many people’s faces. But eating that same fruit a week before it is ripe probably wouldn’t be as enjoyable! Unripe fruits are often hard and bitter, but that serves a purpose. The hard exterior of an unripe fruit protects the developing seed inside. After a seed fully develops inside the fruit, the fruit changes color, softens, and gets sweeter to become more attractive to animals and humans. These organisms eat the fruit and spread its seeds, ensuring the plant’s survival and regrowth.

But how does a fruit ripen? The ripening process involves many complex chemical reactions. When a fruit ripens, it goes through a chemical change. A chemical change happens when bonds within molecules break, and the atoms that once formed them regroup into new molecules. Chemical changes are irreversible. Once a fruit ripens, it cannot become unripe again.

One molecule responsible for this chemical change is ethylene. Ethylene (C2H4) is a colorless gas made up of carbon and hydrogen atoms. (I). It is a naturally occurring molecule in the atmosphere. (II). It is also an important plant hormone. (III). Plants release ethylene through the growing tips of roots, flowers, and ripening fruit. (IV). Although ethylene serves other purposes in plants, one of its main purposes is to trigger the chemical reactions that cause fruits to ripen. As the fruit matures, oxygen in the air helps stimulate the production of ethylene. This ethylene production is a signal that begins fruit ripening. For that reason, unripe fruits have low levels of ethylene, while ripe fruits have higher levels of ethylene. Most fruits produce ethylene and respond to ethylene in the atmosphere.

Although fruits require ethylene to ripen, different types of fruits respond to this molecule in two distinct ways: non-climacteric fruits and climacteric fruits. Non-climacteric fruits do not ripen after harvesting. They produce very little ethylene of their own. Climacteric fruits, on the other hand, continue to ripen after they are picked. These fruits produce a large amount of ethylene. Climacteric fruits can also speed up the ripening process of other fruits nearby since they release high levels of ethylene into the air.  

The phrase These organisms in paragraph 1 refers to...

Phát biểu nào không đúng khi nói về tia tử ngoại?

Một người thợ mộc tốn 6 giờ để làm một cái bàn và 4 giờ để làm một cái ghế. Gọi x, y lần lượt là số bàn và số ghế mà người thợ mộc sản xuất trong một tuần. Viết bất phương trình biểu thị mối liên hệ giữa x và y biết trong một tuần người thợ mộc có thể làm tối đa 50 giờ.

Đồng vị phóng xạ (⁶⁰Co) phát ra tia γ có khả năng đâm xuyên mạnh, dùng điều trị các khối u sâu trong cơ thể. Cobalt có ba đồng vị $^{59}_{27}Co$ (chiếm 98%), $^{58}_{27}Co$ và $^{60}_{27}Co$, nguyên tử khối trung bình là 58,982. Xác định hàm lượng phần trăm của đồng vị phóng xạ ⁶⁰Co.

Ở người, sau bữa ăn nhiều tinh bột, nồng độ glucose trong máu tăng lên. Để điều hòa lượng glucose trong máu, cơ thể không thực hiện phản ứng nào sau đây?

Đoạn văn miêu tả cảnh Đăm Săn múa khiên có sử dụng biện pháp nghệ thuật nào?

Trong Tổng khởi nghĩa năm 1945, nhân dân Việt Nam tiến hành hoạt động nào sau đây?

Hành vi nào sau đây chưa thực hiện pháp luật về ngân sách nhà nước?

Read the following advertisement about a new travel platform and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 1 to 6. (1,5 points)

DISCOVER NEW TRAVEL BUDDIES WITH TRAVELMATE

"Who will you explore your next destination with? Will they share the same (1) ____________ for adventure, or will they prefer a more relaxing trip?" If you often wonder (2) ____________ your travel companions before your next vacation, we have exciting news for you! TravelMate, a (3) ____________, allows you to select your future travel buddies before your trip. This service is designed to give you a more enjoyable and personalized experience. All you need to do is share your travel preferences with the platform, and you'll be matched with others (4) ____________ similar tastes. Whether you're looking to make new friends or reconnect with previous ones, TravelMate (5) ____________ it easy. If you're seeking adventure or simply want (6) ____________ a relaxing getaway, there's a perfect match waiting for you!

Những động vật nào sau đây sinh trưởng và phát triển qua biến thái không hoàn toàn?

Kí hiệu nào sau đây để chỉ $\sqrt{5}$ không là số tự nhiên?

Một chất điểm dao động điều hoà với phương trình . Li độ của chất điểm khi pha dao động bằng là

Read a flyer promoting a new gym. Decide if the statements are true (T) or false (F). 

About us

You don't want just a gym membership. You want a membership that means something. And that means you need support, expert help and a community.

Best Body Fitness isn't just a gym: it's a full-service fitness membership made for you.

Here's how it works:

STEP ONE: Your assessment

We begin with an assessment session. This is a chance for you to see what we do at Best Body. Our assessment plans are no-cost and no-risk. We'll also make a training plan specifically for you.

STEP TWO: Your training

When you decide to become a Best Body member, we show you what to do, how to do it and why you are doing it. After a few sessions with an expert private trainer you will feel comfortable working out on your own. But don't worry, we'll always be nearby if you have questions.

STEP THREE: Your membership

Membership works on a month-to-month basis. There are no sign-up fees and no cancellation fees. Start and stop whenever you want. And the best part? Our fees are the most competitive in the whole downtown area.

STEP FOUR: Your community

At Best Body Fitness, we see everyone as part of a big team. And when you work with a team, you can do great things. Join any of our specialized classes, led by expert instructors. Come to our nutrition classes. Participate in our regular social events. Everything is included in your fee.

The first visit to the club is free.

Hệ thống pháp luật Việt Nam được thể hiện qua đâu?

Trong tự nhiên, tỉ lệ đực : cái thường xấp xỉ

Tình trạng mất an ninh lương thực vẫn còn nghiêm trọng ở khu vực nào dưới đây?