______arriving at the spot, the policemen at once helped the passengers to safety.

查看本题答案

包含此试题的试卷

free spot，target direct，omni free spot，target direct，omna free spot，target direct，omna free spot，targe tdirect，omni spot

two large sunspots a large spot and a small spot the two spots in a spot pair the central core and the ring around if

To arrive 　　　 On arriving 　　　 As arriving 　　　 While arriving

were made by ancient astronomers started in the early 17^th century were made by Galileo only could be made without a telescope

in a spot on the spot off the spot to the spot

at spot on the spot in the spot at the spot

two large sunspots a large spot and a small spot the two spots in a spot pair the central core and the ring around it

at spot on the spot in the spot at the spot

at the spot on the spot for the spot in the spot

To arrive On arriving As arriving While arriving

in a spot on the spot on this spot in the spot

on the spot in a spot under the spot on a spot

were made by ancient astronomers started in the early 17^th century were made by Galileo only could be made without a telescope

As soon as arriving Upon he arrived On arriving Upon arriving at

Arriving at On arriving When arriving Arrived

clear it clear to you clear to you it is clear

at the spot on the spot for the spot in the spot

on the spot in a spot under the spot on a spot

in a spot on the spot from the spot in the spot