1、 ,let me introduce myself to you .
A.To begin with B.Beginning with C.Begin with D.To the beginning
2、The old professor seems something serious.Don’t bother him.
A.to think of B.to have thought of C.thinking of D.to be thinking of
3、We’re glad to learn some of our products have reached world level.
A.advancing B.to advance C.advance D.advanced
4、Is this zoo we visited last year?
A.to which B.the one C.where D.that