英语单选, 希望有详解,谢谢,第四题最好比较一下

英语单选, 希望有详解,谢谢,第四题最好比较一下
1.-Do you think they can keep our classroom clean ?
-——
AI don‘t believe
BI don‘t believe it
CI believe not so
DI believe not
2. When his mother asked him,he admitted —— the vase and said sorry to her
A to break
B to have broken
C breaking
D having been broken
3. Since you are all new comers here ,try not to make——to strangers .
A ways
B connections
C means
D approaches
4. The guidebook is written in——easy English ——beginners can understand
A such ,that
B such,as
C so,that
D too ,that
5. All of us were very excited at the sight of two five-star red flags rising in the stadium,two pairs of Chinese athletes ——at the moment .
A awarded
B are being awarded
C being awarded
D awardeding
6. The man dressed quickly ,——hurriedly grabbed his briefcase and hurried off down the hotel corridor
A shave
B shaving
C to shave
D shaved