Constant correction of speaking ‘errors’ by a teacher is often counter- productive, as student may become afraid to speak at all.

Cho lục giác đều ABCDEF và O là tâm của nó. Đẳng thức nào dưới đây là đẳng thức sai?

She was unhappy that she lost contact with a lot of her old friends when she went abroad to study.

You should not wear casual clothes to the interview. The first impression is very important.

My younger brothers are obedient most of the time, but they are quite mischievous sometimes.

She gave an impeccable reading of the sonata and had the audience on their feet.

Cho lục giác đều ABCDEF và O là tâm của nó. Đẳng thức nào sau đây sai?

I’m sorry to say that it seems you’ve been shirking your responsibilities.

In Western culture, it is polite to maintain eye contact during conversation

She decided to remain celibate and devote her life to helping the homeless and orphans.

Names of the people in the book were changed to preserve anonymity.

These were the people who advocated using force to stop school violence.

Although it’s a long day for us, we feel we are contented with what we do

Một cột đèn có bóng trên mặt đất dài 7,5 m. Các tia nắng mặt trời tạo với mặt đất một góc xấp xỉ bằng 42°. Tính chiều cao của cột đèn (làm tròn đến chữ số thập phân thứ ba).

. Tính đạo hàm của hàm số  $y=\frac{x-1}{4^x}$.