Choose the suitable word in the box to fill in each gap:

Many people nowadays have to wear false teeth when they are middle-aged. The reason is that tooth decay increases a lot. The amount to sugar in our food also increases. Doctors and dentists now know that sugar is the chief cause of tooth decay. Eskimos' teeth , for example, started to decay when they began to eat sweeter food.

Long ago doctors did not like to treat people's teeth. Barbers and blacksmiths looked after people's teeth and pulled them out when they decayed. Some people thought toothache was a punishment from the gods.

Chuc bp hoc tot

arm là tay 

leg là chân 

chest là ngực 

hair là tóc 

các bạn cho mk vài li-ke cho tròn 680 với 

Bài 1: 

3ⁿ + 3^{n + 1} + 3^{n + 2} + 3^{n + 3} = 7085880

=> 3ⁿ(1 + 3 + 3² + 3³) = 7085880

=> 3ⁿ.40 = 7085880

=> 3ⁿ = 7085880/40

=> 3ⁿ = 177147

=> 3ⁿ  = 3¹¹

=> n = 11

\(=\left(2+2^2\right)+.....+\left(2^7+2^8\right)\)

\(=\left(2+2^2\right)+....+2^6\left(2+2^2\right)\)

\(=6+...+2^6\cdot6\)

chia hết cho6

đề hơi sai sai

bạn điên rồi ko ải rảnh mô

bp nên siêng 1 tí đi nhác vừa thôi thế khác gì cho bp cả quyển luôn

đã thế rồi còn ra yêu cầu màu hồng 2017 nữa chứ điên wa mà

Bạn thật ngốc khi chụp đề ko ra trò trống j cả

Chia động từ trong ngoặc :

1. I (live) live here since last week.

2.We (not see) didn't see her since yesterday.

3.Nam (learn) has learnt English for two years.

chia động từ trong ngoặc:

my father used to smoking a lot two years ago