The Shadow knew that no one could have observed his arrival.

He did not observe the passenger's arrival until the tall personage spoke in a quiet tone.

Some one must have observed the coupe's arrival, for the sliding door opened sidewise.

A single of fleer of the ship observed their arrival.

No one, as far as I could tell, had observed my arrival.

"How much time do you need to get away, and can we observe the tools' arrival through something bigger than this airlock port?"

The drill duty crew observed their arrival without any particular interest.

We are lucky in one respect only, that we have observed his arrival.

Both were too concerned with their own affairs to observe Ted's arrival in the doorway.

Professor Hagger must have observed my arrival, because he came out of the farmhouse to join us.