It is thought that the train hit a boulder that had fallen down a cliff on to the track.

人们认为这列火车撞到了从悬崖滚到铁轨上的大圆石。

It is thought that these grooves help to channel water through the mouth and out the gill slits, thereby reducing water resistance.

人们认为这些沟槽有助于将水从嘴中输送到鳃裂外，从而减少水的阻力。

It is thought that being overweight may also increase the risk of cancer in the reproductive organs for women and in the prostate gland for men.

人们认为，超重还可能增加女性生殖器官和男性前列腺患癌的风险。

It is thought that a management buyout is one option.

管理权收购被认为是一个选择。

It is thought that originally these were Hindu or Buddhist nations.

它最初被认为是印度教和佛教国家。

It is thought that the smaller galaxy has actually passed through the larger one.

据认为，较小的星系实际上穿过了较大的一个。

It is thought that more than 400 have gone missing in the last financial year alone.

而仅去年一财年就有超过400人不知去向。

It is thought that our memory of what we have eaten plays a key role in dampening appetite.

据认为，记忆在进食过程中有着重要的作用，它能抑制我们的食欲。

It is thought that no coal plant of this size has been converted anywhere in the world.

在世界范围内，目前还没有一个如此规模的煤炭工厂转型成功。

It is thought that exposure to allergens - from cats and dogs - could boost the immune system.

这是因为从猫和狗那里接触过敏原，能够增强人们的免疫力。

It is thought that the first machines will be built in 2013-14 following two years of testing.

预计在经过c两年试验后，第一台机组将于2013-2014年建成。

It is thought that soya, a vegetable protein, somehow interferes with the processing of excess sugar into fat.

腹部脂肪对健康尤为不利，它比身体其它部位的脂肪更能增加心脏病和糖尿病的风险，作为植物蛋白的大豆能阻断过剩糖类变成脂肪的过程。

It is thought that sulphur produced by volcanoes erupting led to oxygen disappearing from large areas of the oceans.

据认为，由火山喷发产生的硫磺使氧气从大片海域消失。

It is thought that one of the reasons we splash our cash or help others is simply because it makes us feel good.

人们认为，这其中的一个原因就是我们挥金如土或者帮助他人，也仅仅只是因为花钱这个行为能够让我们感觉良好，本意并非为他人着想。

It is thought that the human brain grew so large, and our species became so clever, as our social groups expanded.

人类大脑成长到如此之大，我们的物种变得如此聪明，这都是因为我们的社交组织得到了扩展。

It is thought that many firms are reluctant to report cyber attacks out of fear that it would damage their reputation.

很多公司被认为由于担心损害自己的信誉而不愿举报网络攻击。

It is thought that high levels of fat raise the odds of the arteries clogging up, cutting the flow of blood and oxygen.

高水平的脂肪含量会使得动脉更易堵塞，并降低了血液与氧气的流动。

It is thought that the iPad 2 only USES a sub-1MP camera in the rear, which is good enough to shoot 720p, but not 1080p video.

ipad 2被认为仅会配备一枚100万像素的背部摄像头，且能拍720p的视频，不能拍摄1080p的视频。

It is thought that early man then left Africa around 80,000 years go - taking with him some of the diversification but not all of it.

研究认为，非洲的早期人类在大约8万年前离开非洲，并带走了一部分的语言。

It is thought that such twists and turns of the neck and torso are attractive because they signal a strong, healthy and flexible body.

女人们认为脖颈和身躯的转动和扭转代表着身体强壮、健康和具有柔韧性，故而具有吸引力。

It is thought that most of the thousands of buildings that collapsed were built before 1981, when building standards were tightened.

据信，数以千计的倒塌建筑物中，有许多是1981年建筑标准提高之前建造的。

It is thought that more damage was done by the resulting fire after the 1906 San Francisco earthquake than by the earthquake itself.

有证据表明，在1906年的旧金山大地震中，地震后导致的火灾所造成的破坏大于地震本身所造成的破坏。

It is thought that they receive more exposure to pesticides during the first few months of pregnancy - a critical time for brain development.

据认为，这是因为这些小孩在孕期的头几个月接触更多的杀虫剂所致，而这几个月正是大脑发育的关键时期。

Although offical, hard data is not available, it is thought that total annual revenue streams in 2008 were approximately USD 300 million.

虽然官方的准确数据难以获得，但据猜测2008年全年的收入大概是3亿美元。