1.The circuit of a motor racing track is 3 km in length. In a race, a car goes 25 times round the
circuit in 30 minutes.
What is the average speed of the car?
A 75 km / hour
B 90 km / hour
C 150 km / hour
D 750 km / hour
2. A sample of a solid is heated for 12 minutes and its temperature noted every minute.
The results are shown in the table.
time / min 0 1 2 3 4 5 6 7 8 9 10 11 12
temperature / °C 11.5 16.1 22.1 31.0 31.1 31.1 31.1 31.3 45.0 65.2 66.2 66.3 66.3
How should the sample be described at the end of the 12 minutes?
A all solid
B in the process of melting
C all liquid
D in the process of boiling
thanks in advance