玛丽当众讲话时总是很自信.
Mary is always confident when she speaks .
The artist always (表达) his world view in his works.
Although you are young,you can (仍然) make the world more beautiful in your own way.
Our government has made laws to (限制) air and water pollution.
If you go to ,you'd better not miss the Opera House in Sydney.
All children between the age of 5 and 16 in his country must (go to)school.