1b technology1c I development of effective insecticides.1cii invention of machine such as tractors

1di veterinarian1dii architect

2b i to control the size of the air hole2b ii to allow air flows into the barrel

2c non-luminous flame/ blue flame2d i it is blue in colour2d ii it is very hot.

3a 86cm3

3b Q3c meniscus3di place the measuring cylinder on a flat surface.3dii when taking a reading, ensure that the position of the eye is at the same level as the water.

4a 1.1, 1.5, 1.8, 2.04b 214c the longer the length of the pendulum, the longer the time taken for one swing.4di mass of the pendulum4dii length of the pendulum4diii period of oscillation4e the longer the length of the pendulum, the longer the period of oscillation.4f by plotting a graph of the time taken for one swing against the length of the pendulum.