-You look so worried, what’s wrong? -More and more people like me begin to worry about the ______ pollution after the haze (雾霾) appeared in Beijing and some other cities in China.
Detective Wang, please trust me, I have ______to do with this case..
Our Chinese teacher encouraged us _______ up even if we made a serious mistake in our writing work.
A Wechat(微信) is an invention ______ can help people talk to friends , share photos, ideas and feelings freely.
He has spent as much time as he has _______ English in the morning.
We're not sure if it _______ tomorrow. If it _______, we won't go hiking.