Stephen Hawking， a great scientist， died ________ the morning of March 14， 2018．（ ）
A．onB．inC．at
I have never been to Beijing for the summer holidays，and ___________ he．（ ）
A．so hasB．neither has
C．so haveD．neither have
I'll spend as much time as I can ________in an old people's home．（ ）
A．helpB．to helpC．helping
I'm not sure whether we can have a picnic on Saturday evening，because it _________the weather．（ ）
A．stands forB．lives on
C．agrees withD．depends on
He______be in the classroom，I think．
No，he____be in the classroom．I saw him go home a minute ago．（ ）
A．can； may notB．must； may not
C．may； mustn'tD．may； can't
He ______ a book yesterday．It ______ him 50 yuan．（ ）
A．bought； paidB．spent； took
C．paid； spentD．bought； cost