单项选择题
His name was on the ______ of my tongue, but I just couldn't remember.
单项选择题 Doctors often make higher ______ for their works than they should.
单项选择题 Though it was late in the night, ______ he continued to work vigorously.
单项选择题 One of the most spectacular qualities of man is notably his ______ to any kind of natural environment.
