Last summer I took a course on ______ poisonous gases.
____ he comes to Nanjing he will go to the Eastern Suburb for sightseeing.
She saved her money ___she might buy a color TV set.
The doctor must have sat up all night with his patient, __ you see, he looks tired and sleepy.
It’s quite warm __December in China.
The mountains look grey ___ the blue sky.