Read the given passage and answer the questions that follow.

We sit in the last row, bumped about but free of stares. The bus rolls out of the dull crossroads of the city, and we are soon in the open countryside, with fields of sunflowers as far as the eye can see, their heads all facing us. Where there is no water, the land reverts to the desert. While still on level ground, we see in the distance the tall range of the Mount Bogda, abrupt like a shining prism laid horizontally on the desert surface. It is over 5,000 metres high, and the peaks are under permanent snow, in powerful contrast to the flat desert all around. Heaven lake lies part of the way up this range, about 2,000 metres above sea level, at the foot of one of the highest snow-peaks.

As the bus climbs, the sky, brilliant before, grows overcast. I have brought nothing warm to wear. It is all down at the hotel in Urumqi. Rain begins to fall. The man behind me is eating overpoweringly smelly goat’s cheese. The bus window leaks inhospitably but reveals a beautiful view. We have passed quickly from the desert through arable land to pasture and the ground is now green with grass, the slopes dark with pine. A few cattle drink at a clear stream flowing past moss-covered stones; it is a Constable landscape. The stream changes into a white torrent, and as we climb higher I wish more and more that I had brought with me something warmer than the pair of shorts that have served me so well in the desert. The stream (which, we are told, rises in Heaven Lake) disappears, and we continue our slow ascent. About noon, we arrive at Heaven Lake, and look for a place to stay at the foot, which is the resort area. We get a room in a small cottage, and I am happy to note that there are thick quilts on the bed.

Standing outside the cottage, we survey our surroundings. Heaven Lake is long, sardine-shaped and fed by snowmelt from a stream at its head. The lake is an intense blue, surrounded on all sides by green mountain walls, dotted with distant sheep. At the head of the lake, beyond the delta of the inflowing stream, is a massive snow-capped peak which dominates the vista; it is part of a series of peaks that culminate, a little out of view, in Mount Bogda itself.

For those who live in the resort, there is a small mess-hall by the shore. We eat here sometimes, and sometimes buy food from the vendors outside, who sell kabab and naan until the last buses leave. The kababs, cooked on skewers over charcoal braziers, are particularly good; highly spiced and well-done. Horse’s milk is available too from the local Kazakh herdsmen, but I decline this. I am so affected by the cold that Mr. Cao, the relaxed young man who runs the mess, lends me a spare pair of trousers, several sizes too large but more than comfortable. Once I am warm again, I feel a pre-dinner spurt of energy—dinner will be long in coming—and I ask him whether the lake is good for swimming in

What is the tone of the passage?