have been to

v.

曾经到过；

Identification of the MATa mating-type locus of Cryptococcus neoformans reveals a serotype A MATa strain thought to have been extinct.
Two CD1 genes map to the chicken MHC, indicating that CD1 genes are ancient and likely to have been present in the primordial MHC.
The related genes encoding growth hormone and prolactin have been dispersed to chromosomes 10 and 17 in the rat.
HOW WE HAVE BEEN LEARNING TO TALK ABOUT AUTISM: A ROLE FOR STORIES
Is coding for myocardial infarction more accurate now that coding descriptions have been clarified to distinguish ST-elevation myoca...
Compendium of botanicals that have been reported to contain toxic, addictive, psychotropic or other substances of concern on request...
Evaluation of radiometric ages pertaining to rocks hypothesized to have been derived by hotspot activity, in and around the Atlantic...
Evaluation of radiometric ages pertaining to rocks hypothesized to have been derived by hotspot activity, in and around the Atlantic...
Seven historically Black colleges and universities have been selected to participate in a new grant initiative to develop community ...
Methanol intoxication. How to help patients who have been exposed to toxic solvents.