In a courtroom it is sometimes difficult to ______ who is innocent and who is guilty.
Two percent of the total poulation of China have ____ access to the Internet,____ with 45 percent in the USA and 15 percent in Japan.
We live in ____ neighbourhood of the school and go to school on ____ foot.
There are lots of plastic bags ____ in the river, ____ it very dirty.
--- Would you mind if I used your bike? --- ____.
The president spoke at the business meeting for nearly an hour without ____ his notes.