At times the balance in nature is ______ , resulting in a number of possibly unforeseen effects.
Good technique in medicine means less pain and fewer deaths and, ______ it’s our duty to master it.
In the group discussion, they thought up three different __________to solving the environmental problem.
The population of India has ______ quickly, because they don’t have a Family Planning policy like China.
As our country has realized the problem and taken some measures, the price of medicine has _______ and poor people can also afford good medicine.
Although there were so many people in the square , I could ___________my friend the moment he appeared .