This is in response to your question: Could you please tell me why you used "looking at buying"? You wrote the following in your text above: "As a newcomer, I noticed that many people are looking for buying their needs from the Amazon..." The way I wrote it is the correct English. It's "looking at buying what they need" in this context and not "looking for buying their needs".

If you want to be a seller in North America you should have earned many credits. There are plenty of registered e-commerce websites that are making it more difficult to go through with this. As a newcomer, I've noticed that many people are looking at buying what they need from the Amazon due to its popularity. (I WOULD USE EITHER OF THE NEXT TWO SENTENCES:) They know that a big company is behind it. OR They know that a big company manages it. There is, therefore, no need to worry when purchasing any number of items. Basically, the staff costs of warehouses are high, whereas online shopping stores don't have this kind of expense. Therefore, costs will be decreased with as much as thousands of dollars. Vital shipping services are the most important part of this process. Most of the items are returnable within 30 days of purchasing. Therefore shipping services should act faster and return the dispatched items if required by the clients.

1: If a company failed to obtain a good employee management system, it will suffer from both explicit loss and people's willingness to work for them. 2: Imagine you are on a beach packed with people who are yelling, screaming, playing, and throwing garbage or even peeing in the sea, will you still love the coast-scenery kind of holiday so much. 3: How about the public servant exam? Don't even mention it! It was so difficult that I not only didn't finish it, but I'm not even sure whether the things I've filled in were correct. This caused me to have filled the last ten blanks with Cs at the last minute. It was terrible!

What is it you want to do Zeeshan? Do you want to practice speaking English, or do you need more classes?

It's a difficult question to answer if I don't know what you've done to develop your English. Have you had classes and if so, how many, how many opportunities do you get to practice your English, etc. Would you like to send me a message to my message inbox so we could discuss this?

either of them was fine

If you use 'had thought' here it means the scientists had thought it before, but don't anymore. Using 'thought' instead in this context would be better yes. The past perfect is usually used when the rest of the sentence is in the past tense as you've stated.

How about: I'm looking forward to having a relaxed time during our next get-together in the summer.