[micaelo]

In the following fill-in-the-gap exercise:
Some other nations did the occasional scrawl when listening ..., but the British were undoubtedly the most compulsive of all those attending.

a ecstatically B calmly C raptly D alertly
Obviously, the correct option is C raptly, but I was wondering about the meaning of "listening alertly", I feel it means to listen as if expecting the other person to make a mistake or say something objectionable. Am I correct here? Thank you.

[mesmark]

If you were listening 'alertly', you'd have to be listening alertly for something. not to something. Unless, you were litening 'toward' something.

He listened alertly to the night. (but for some noise.)

So, yeah. I think you are correct, but it doesn't have to be for a mistake or something objectionable.

Although, I think I'd actually question its usage and probably recommend students use 'carefully' or something else instead.

[FionaVB]

Actually, I'd have to question the "obvious" answer. 'Rapt' means 'deeply engrossed'. The sentence seems to be talking about people doodling while listening. I can't imagine someone doodling while listening either raptly or alertly (and I dislike both of those adverbs, for some reason!) 'Calmly', on the other hand, does convey the impression of someone sitting at a desk, aware of the speaker but with part of their mind on something else.
Is this being too picky? Sorry...