1.lead to 導致
A number have orbits that take them closer into the solar system that sometimes lead them to collide with Earth or the other inner planets.
有很多小行星的軌道可以把它們帶到太陽系的更內層，有時甚至會使它們與地球或其它內行星相撞。

2.in herds 成群
Adult females and young travel in herds, while adult males generally travel alone or in groups of their own.
成年母象和小象會在群體中活動，然而成年公象一般會獨自活動或者在他們的群體中。

3.a bunch of 一群
He responded instantly: as a bunch of ostriches with their heads in the sand.
他立刻答道：它們就像一群把頭埋在沙子里的鴕鳥。

4.Or so 至少；大約
The typewriter remained in good condition after having been used for ten years or so.
這臺打字機用了大約十年了，還這么好。

來源:可可英語 http://www.ccdyzl.cn/Article/201611/480940.shtml