You can't just count upon one single person to get the work done properly.

单指一个人是不能把事情做好的。

《新英汉大辞典》

Obviously, it is far easier to count the number of vaccines, bednets, and medicines distributed by single-disease initiatives than it is to measure the impact of WHO’s technical work.

显而易见，对通过单一疾病行动分发的疫苗、蚊帐和药物进行计数要比衡量世卫组织技术工作的效果容易许多。

youdao

Today I am 39, with too many ex-boyfriends to count and, I am told, two grim-seeming options to face down: either stay single or settle for a “good enough” mate.

现在我三十九岁了，交往过的前男友难以计数，而且，人们告诉我必须面对两个看似严酷的选项：要么保持单身，要么找个“还可以”的伴儿安定下来。

youdao

So minimum would be three, the maximum would be eight for the single count.

CNN: D.A., sheriff discuss Jackson allegations

They spoke only to confirm their names and enter not guilty pleas to the single count of murder.

BBC: Wells-Burr death: Boyfriend Rafal Nowak denies murder

Mr. Taylor pleaded guilty to a single count of wire fraud, which carries up to 20 years in prison.

WSJ: Ex-Goldman Trader Pleads Guilty to Fraud