But for friction (摩擦力), people ______ neither walk, nor even stand up.
| A．can | B．were able to | C．will be able to | D．could |
Mary's birthday ________ on a Sunday this year.
| A．falls | B．finds | C．forecasts | D．founds |
--- Please _______ us in the discussion.
--- I’d like to, but I’m _______ busy at present.
| A．attend；too | B．take part in；much |
| C．join；much too | D．join in；too much |
After the wedding ceremony, all the guests attended a reception, _______ lasted through the night.
| A．that | B．when | C．where | D．which |
In front of my house_______, full of apples.
| A．a big tree stands | B．does a big tree stand |
| C．stands a big tree | D．standing a big tree |
We're fully_______ that we'll solve all problems and finish our task in time
| A．confident | B．generous | C．urgent | D．nervous |