It is reported that a kind of new smart phones can test the air quality（质量）around you．
__________fast the technology develops! （ ）
A．WhatB．What aC．HowD．How a
As students， we should______ourselves． We can't spend much time playing computer games．（ ）
A．be responsible forB．be proud of
C．be popular withD．be thankful to
Larry hopes_____his English， so he keeps practicing it every day．（ ）
A．to solveB．solvingC．to improveD．improving
Mount Lao is one of_____mountains in Qingdao． Many tourists like climbing it every year．（ ）
A．famousB．the more famous
C．most famousD．the most famous
It is raining heavily，_____none of the students are late for school．（ ）
A．althoughB．butC．soD．because
I can't find my mobile phone．
Don't worry． Maybe you_____it at home．（ ）
A．forgotB．missedC．lostD．left