The chemistry teacher asked the students ________ more attention _________the lab clean.
| A．to pay ,to keep | B．to paying ,to keeping |
| C．to pay , to keeping | D．paying ,keeping |
---- My best friend left me because I hit him on the face last night .
----______________ .You were so rude.
| A．It serves you right | B．So you did |
| C．So did she | D．It depends |
---- If you don’t know what the new words mean , ________- in a dictionary .
| A．look them up | B．look them down |
| C．look them after | D．look them over |
---- ______ you ever ______ aboard ?--- Yes, but only once.
| A．Do ,travel | B．Have traveled |
| C．Did travel | D．Were traveling |
---Why didn’t the little boy raise his hand in class today ?
---- Maybe the questions are ______ difficult for him_______ answer .
| A．too, to | B．enough ,to |
| C．not ,to | D． so ,that |