3a. Hòa tan 58.5 gam Natri Clorua vào 100ml H2 . Tính nồng độ % chất tan trong dung dịch 3b. Hòa tan 3.9g Kali vào 100ml H2O. Tính nồng độ % chất tan trong dung dịch 3c. Tính % các nguyên tố trong : C12H22O11 ; CuSO4; H2S; SO2 Nguyên tử ? Phân tử ? Chất ? Đơn chất ? Hợp chất ? Thành phần cấu tạo của nguyên tử ?

As  you know  in this life, English as using a very important position.  English is considered the second most widely spoken language in the world (after Chinese). Do you know why English is so widely used ???? By it may be able to help you access the job that is attractive and suitable for you. When you have a good job , it is also a premise for you to help you succeed at work. And in this life you have to communicate with someone and if unfortunately it's a foreigner and the worse thing is they don't know, understand what you're saying, can't you just shut up and smile confidently for them. ? Passed ? If you know English , kt won't be different for you. It's also helps you feel confident when communicating with someone anf maybe you have  a good relationship.  So try to learn English because it's bring a lot of benefits to you.  " A happy life or miserable life is done by you today"- Ngọc Như

Hello Jocasta,

 It's me here is your Nessy. Long time no see you, do you miss me ? How have you been lately ? Me and my family are in good health.  I heard that you intend to come VN to play right ? So when did you come here ? If you come VN, please call to me and i will take you around VN by cyclone or motorbike or bus and even by train. I'm sure you will love it forever. 

Hope to see you soon,

Jacasta's cute pen-friend

Nessy

Hello Jocasta,

1 has lived

2 has driven 

3 have tried/have you done 

4 have looked

5 have smoked

6 has dated 

7 have operated 

8 have worked 

9 has traveled 

10 have you done/ have cleaned 

11 has learned or has learnt đều được 

12 have thought 

Chỉ mình bài 2 câu b với câu chứng minh ấy