several简单

Several American cities are mentioned to show ____

文中提到几座美国城市是为了说明____

If you look at the apps on your phone, chances are you have at least one related to your health — and probably several.

如果你看看手机上的应用程序，很可能至少有一个与你的健康有关——而且可能有好几个。

[As a result], these structures became important centers for cultural [exchange] and interaction, with travellers sharing their cultures, ideas and beliefs, [as well as] taking knowledge with them, greatly [influencing] the development of several civilisations.

因此，这些建筑成为文化交流与互动的重要中心，旅行者在此分享各自的文化、思想和信仰，并把知识带走，极大地影响了多个文明的发展。

Throughout the trip, Jackson juggled multiple cameras and plate sizes using the “collodion process” that required him to coat the plates with a chemical mixture, then expose them and develop the resulting images with a portable darkroom. The crude technique required educated guesses on exposure times, and involved heavy, awkward equipment — several men had to assist in its transportation. Despite these challenges, Jackson captured dozens of striking photos, ranging from majestic images like his now-famous snapshot of Old Faithful, to casual portraits of expedition members at the camp. While veterans of previous expeditions wrote at length about stunning trail sights, these vivid photographs were another thing entirely.

在整个旅途中，杰克逊使用“火棉胶工艺”同时摆弄多台相机和多种尺寸的底片，这种工艺要求他先给底片涂上一层化学混合物，然后曝光，再用便携式暗室冲洗出影像。这种简陋的技术需要凭经验推测曝光时间，而且所用设备笨重难使——需要好几个人协助搬运。尽管困难重重，杰克逊还是拍下了几十张引人注目的照片，从他那张如今已闻名于世的老忠实泉快照这样的壮丽画面，到营地里考察队员的随意肖像，不一而足。以往考察的老手们曾长篇累牍地描写沿途的壮丽景色，而这些生动的照片则完全是另一回事。

She is proud that several sculptures have even gone on display again, albeit sometimes beneath protective cases.

令她自豪的是，有几件雕塑甚至重新展出了，尽管有时是放在保护罩下面。

Fewer artists than scientists responded to the Nature poll; however, several respondents noted that artists do not simply assist scientists with their communication requirements.

回应《自然》调查的艺术家比科学家少；不过，有几位受访者指出，艺术家不只是协助科学家满足其传播需求。