如果
_____ it is very late now, the researchers are still working in the lab.
\_\_\_\__ it is very late now, the researchers are still working in the lab.
Generally, snakes won’t attack humans _____ they are threatened with danger.
Generally, snakes won’t attack humans \_\_\_\__ they are threatened with danger.
The word “address” in Paragraph 1 is closest in meaning to _____.
The word “address” in Paragraph 1 is closest in meaning to \_\_\_\__.
According to Ban the Bottle, drinking bottled water costs _____ dollars per year.
According to Ban the Bottle, drinking bottled water costs \_\_\_\__ dollars per year.
With the guide _____ the way, we set off on foot into the dark night.
With the guide \_\_\_\__ the way, we set off on foot into the dark night.
汽车紧急刹车后做匀减速直线运动，经2s后停下．如果在这个过程中汽车的加速度a＝－6m/s2，那么汽车刹车后经过的路程是____m．
汽车紧急刹车后做匀减速直线运动，经2s后停下．如果在这个过程中汽车的加速度a＝－6m/s2，那么汽车刹车后经过的路程是\_\_\_\_m．