Using Relative Clause

Using Relative Clause 
- Mary has won a gold medal in athletic. I know her sister
Điền vào chỗ trống
1. The bus that goes to the city center.........
a. Running every 15 minutes
b. Which runs every 15 minutes 
c. Runs every 15 minutes 
d. It runs every 15 minutes 
2. The picture ........ was very strange 
a. At which i was looking 
b. That i was looking at 
c. I was looking at 
d. All are corcorrect 
3. I gave her 2 books,.........
A. One of them is about Uncle Ho's life 
B. One of that is about Uncle Ho's life 
C. Of that one is about Uncle Ho's life 
D. One of which is about Uncle Ho's life
4. Do you know the woman ....... to the headmaster? 
A. Is taking 
B. That is taking
C. She is talking 
D. Whom is taking