Adsense CPC is proportional to what advertisers are willing to pay per click. Two major factors that determine CPC follow:
Niche - Your website topic may not have high-paying advertisers. For example, advertisers from Niches like healthcare, insurance, etc., tend to spend bigger.
Location - Adsense displays both contextual and personalized ads. CPCs are usually higher in developed countries like the US where income levels are high.
So, if you focus on AdSense, either you should target the right audience or at least the right niche or preferably both.
Update: I am adding more explanation as OP wanted to know if CPC can be as low as 0.007 USD.
0.007 USD translates to 1.40 Srilankan Rupee. 68% of click cost is shared with publishers ( https://support.google.com/adsense/answer/180195?hl=en). So the actual cost spent by an advertiser (on average) is around 2.05 in Srilankan currency. This cost is entirely possible as it is for click and not for a sale or conversion. Assuming an advertiser gets a conversion rate of 1%, he would have spent 100 x 2.05 = 205 per conversion.