-- What can trees do _________ us ?
--- They can _________ harmful gases and produce oxygen .
A．helping , take in B．to help , take in C．helping , take out D．to help , take care
--- Next week , we will go to visit your school .
--- You are welcome _________ our school and you can go _________ to have a look .
A．visit , somewhere B．to visit , anywhere C．to visit , nowhere D．visiting , anywhere
--- Tom is one of _________ students in my class .
--- Yes . He usually prefers _________ at home to playing outside .
A．the most hard-working , studying B．more hard-working , to study
C．the most hard-working , to study D．more hard-working , studying
--- We don’t allow _________ in the library .
--- So we had better _________ outside .
A．smoking , smoking B．to smoke , smoking
C．to smoke , to smoke D．smoking , smoke
-- Shenzhen _________ on the coast .
--- Yes . It is _________ the north of Hong Kong .
A．lies , in B．is , to C．is , in D．lies , on
--- Why did you _________ school late today ?
--- Because I _________ late this morning .
A．arrive at , woke up B．arrive in , wake up
C．arrive at , wake up D．arrive in , woke up
