保护克罗斯河大猩猩

familiar with熟悉的
例句：I am not very familiar with European history.
我对欧洲历史不太熟悉。

2. But over the last hundred years as human population has grown in this area they were hunted down to a very small level of 250 to 300 individuals scattered across 13 little pockets on the border of Nigeria and Cameroon

hunt down搜索直至找到(某物)
例句：The police have hunted down the escaped prisoner.
警方已经追捕到了那个逃犯。

3. With actually a lot of support from the U.S. Fish and Wildlife Service and the work of conservation NGOs like the Wildlife Conservation Society we’ve been able to get a handle on where the remaining populations exist.

get a handle on控制，掌握，驾驭，左右；解决
例句：For some reason, I couldn't get a handle on it. 
因为某些原因， 我就是开不了窍。

4. Part of the five-year plan to save the Cross River gorilla is to have local communities act as guardians for the primates.

act as担当…; 起…的作用
例句：An oar often acts as rudder.
桨常可起舵的作用。

5. So how many Cross River gorillas would there have to be in order for the species to be considered safe?

in order按次序的; 合乎程序的
例句：The names are arranged in order.
姓名按顺序排列。

6. The fund allows the service to offer conservation grants ranging from $50,000 to $100,000.

range from to从...变化到...
例句：Prices range from ￡6 to ￡10.
价钱从六英镑到十英镑不等。