单项选择题

Li Lei didn't meet the famous American professor（）he was on holiday last year.

A．unless
B．until
C．if
D．whether

相关考题

Don't leave matches or cigarettes on the table within（）...

单项选择题Don't leave matches or cigarettes on the table within（）of little children.

A．hand
B．reach
C．space
D．distance

She is the one among the women writers（）comic books for...

单项选择题She is the one among the women writers（）comic books for children.

A．whom writes
B．whom write
C．who write
D．who writes

The pen（）on the floor for ten minutes, but no one has p...

单项选择题The pen（）on the floor for ten minutes, but no one has picked it up.

A．is lying
B．has lain
C．has been lying
D．lay