David finds ___ difficult to communicate with his parentsA.one B.it C.this
— Mrs Black is an organized housewife.—That’s right. Everything in her house is always ________.
The railway _______ Qinghai to Tibet is the longest plateau (高原) railway in the world.
Your mobile phone is so good. Where did you buy _____? I want to buy____ too.
— Our monitor Jack is good at all the subjects, but he never ________.— What a modest student!
— Did you enjoy the outdoor training yesterday?— No, not at all! I was ________ dead after so much hard training.