In the past few years, research has suggested that Vitamin D may increase the level of serotonin(血清素), one of the key nurotransmitters influencing our mood, and ________it helps to relieve mood disorders.
I have been living in the United States for twenty years ,but seldom _____ so lonely as now.
_______ that Marie was able to set up new branches elsewhere.
Little ____that we were watching his every move, so he seemed to be going his own way in this business.
----My room gets very cold at night. ---____________.
---How was the televised debate last night? ------Super! Rarely _____ so much media attention.