A. variety
Đáp án A
The emphasis is on oral communication practice in a wide variety of situations at the advanced knowledge: Trọng tâm là thực hành giao tiếp trong một loạt các tình huống ở những kiến thức tiên tiến.
Scientists are unsure of the reason for this (70)_______ on the global scale either.
In this way, we can put you in a (59)_________ at the most suitable level.
The trains which go through the Chunnel can travel at up to 300km/h due to the(31)_________ electrical system.