The dog has been of most value to man in the development of ______.A.a treatment for rabie

The heart disease has been one of the most ______ diseases to endanger the health and resu

The linebacker and captain of the team______most valuable player.A．have been selectedB．has

The ______ of the U.S.S.R. has been the most momentous event of the last quarter of the 20

From the beginning, migration has been one of the most conspicuous features of human histo

The most common use of telecommunication satellites has been for _____ telephone ca

Since ancient times the value of chicken soup______A.has been over-estimatedB.has been wi