1) Cho 0,25 mol CO₂ hap thu het vao dd chua 0,2 mol Ca(OH)₂. Khoi luong ket tua thu duoc la:

A. 20,0         B. 5,0           C. 15,0         D.10,0

1) 1atm = .........Pa

1) Why don't we send them some textbooks, newspapers and picture books?

A. Great idea! What meaningful gifts!                  B. No, they are not available

C. We're sorry to hear this                                   D. You should agree with us

1) When did you have a Facebook account

A. How long do you have a Facebook account

B. How long did you have a Facebook account

C. How long had you had a Facebook account

D. How long have you had a Facebook account

1) e = 3V, r = 0,5Ω, Den (3V - 1,5W) , R_b la bien tro, R_p = 6Ω. R_p la dien tro binh dien phan dd AgNO₃

a) Tim R_b biet den sang binh thuong

b) Tim m_Ag. Sau t = 16'5 (s) ( den sang binh thuong )