Is ____ dangerous to swim in the river alone?

– Which of the e-mails ______ you have ever got is the greatest?– I really can’t decide. ______ of them are very wonderful.

.--- I think this accident happened for many reasons. --- Richard is partly to blame, __________way you look at it.

“Have _______try, you are so close to the answer,” the teacher said to Eric.

You can choose _____book you like in the library.