1.  What's more, they don't know how to be romantic so they probably fail when paying court to girls.

2.  How much do you know about him?

3.  "\

4.  "\

5.  They have known what they want and what they have to do.

6.  "Do you know Lin Chuan? "

7.  "\

8.  You know, like how many kilometers we make when we do seventy miles in the car?

9.  They know everything that other students don't, and they can solve any problem which is far too difficult for others.

10.  She must know how beautiful she was, since she kept looking into the mirror, appreciating herself from different angles.