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are lacking is the most popular phrase on the web.

are lack 1473,000 results on the web	are lacking 16,540,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	Enzyme replacement therapy provides patients with the enzyme they are lacking. In many cases concrete goals, measurable objectives and timetables are lacking. I would like to list three elements which are lacking in my opinion. The relevant precautions are lacking, as is positive assistance to Mexico. But obviously the rest of your manners are lacking. Data are lacking regarding effects on CYP2C8 and CYP2C19. Subsidies are not enough to ensure development when infrastructure and public services are lacking. Above all, important institutional reforms are lacking in regard to the Council and Commission.

are lack

1473,000 results on the web

are lacking

16,540,000 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

Enzyme replacement therapy provides patients with the enzyme they are lacking.
In many cases concrete goals, measurable objectives and timetables are lacking.
I would like to list three elements which are lacking in my opinion.
The relevant precautions are lacking, as is positive assistance to Mexico.
But obviously the rest of your manners are lacking.
Data are lacking regarding effects on CYP2C8 and CYP2C19.
Subsidies are not enough to ensure development when infrastructure and public services are lacking.
Above all, important institutional reforms are lacking in regard to the Council and Commission.