In case of fire, stay low to the ground in a smoky room, ________ smoke always rises towards the ceiling.
19. My grandpa has many hobbies which _________ from collecting stamps to planting flowers.
18. It was ______ back home after the experiment.
17. -- My mother always tells me to try my best _______ many difficulties. -- I can’t agree any more. _______ you put your heart into work, you can overcome them.
16. Charles Babbage is generally considered _______ the first computer.
15. __________ made his mother worried.