Some students have trouble grammar while others have difficulty new words.
One well of the oil field was still burning with huge fire twisting crazily____ the night sky.
— They are said to have been familiar with each other.— But they_________. They were introduced only hours ago.
Nowadays mobile internet devices are pushing up demands for online education, which makes people see it as one of the most____ new market.
— Haven’t seen you for ages! Where have you been?— I____ in Xinjiang for one year, volunteering services as a doctor.
Look, ___beautiful flowers the girl ___carrying that she becomes the focus in the room.