21.   His tracheotomy tube is still in, and he can only talk at certain times.

22.   However, big tubes are difficult to build, and expensive.

23.   If necessary, breathing tubes may be inserted and mechanical respirators used.

24.   Instead, the tube is uniformly gray in the dim half-light of the occasional fluorescent bulb.

25.   Laid out on the table were tubes of Winsor Newton oil paints, brushes, knives, glass dishes, paper towels.

26.   Never do I get through a watering without marveling at how adept these tubes are at grabbing on to something.

27.   On the other hand, since there is no tube involved in virtual colonoscopy, there is no way to cut out a polyp if one is located.

28.   Physicist Paul McEuen of the Lawrence Berkeley National Laboratory believes that carbon tubes could be ideal sensors to explore the chemical environment inside living cells.

29.   Protruding from two portals in the wall behind the gurney were tubes through which the drugs would be transported from syringes to the needles.

30.   Scoop the mixture into a pastry bag and hold so the tube is pointing straight down and pipe out mounds resembling kisses onto the parchment.