我很瘦用英文表达是：I am very thin.

例句：我不觉得自己很瘦，我一直觉得自己蛮胖的。

I dont think Im thin -i always see myself as bigger.

我现在很瘦，但事实并非总是如此。

I'm quite thin now, but that wasn't always the case.

现实是我现在很瘦，我得提着我的短裤。

The reality, though, was that I was now so thin I had to hold my shorts up.

那东西看上去不大，在路的左边弯着腰的样子。当车子的前灯最后照到那东西的时候，我终于看了个一清二楚。它很矮，看上去只有三四英尺高，很瘦，可是手臂却异乎寻常的长。

It looked like something small and hunched down on the left side of the road. As the headlights finally fell upon the thing I saw it fully.

熊很瘦，也不比一头拉布拉多犬大多少，很明显是一头小熊，但毕竟是一头熊，我以有资格参加英国2012年奥运会自行车赛的速度快速逃走。

But it was still a bear. I peddled away quickly enough to have qualified for Britain's 2012 Olympic cycling squad.