Phân tích các số sau đây ra thừa số nguyên tố rồi tìm tập hợp các ước của mỗi số
1) 51                                   2) 80                                          3) 75                            4) 180
5) 105                                 6) 540                                        8) 256                          8) 840

1 Which word has the main stress placed differntly from the other
   a. doctor            b. dentist            c. biology       d. fantasy
2 Which word has the main stress placed differntly from the other
     a. necklace      b. activity           c. chocolate    d. restroom 
3 Which word has the main stress placed differntly from the other
 a  unhealthily       b. laundry          c.housework           d. countryside
4 Which word has the main stress placed differntly from the other
  a . seafood         b. apartment     c.  stranger             d.popular
5 Which word has the main stress placed differntly from the other
  a. geography     b. photography   c. Vietnam           d. continent

 bài 1: Tính hợp lí 
a)  21 x 17 - 17.10-17

b) 18 x 27 + 18 x 73 - 700

 Writing
I. rewrite the  following sentences with the given beginnings in such a way that the meanings stay unchanged
1 There are three bedrooms in my house.
→ my house_____________________________________________________________________________
2. This house is very small
→ This is ________________________________________________________________________________
3. My mother teaches at this school.
→ My mother is ___________________________________________________________________________