A. The students are waiting the teacher A. to B. at C. for D. a&b
b. she needs those medicines.
A. has B. to read C. reading D. to reading
d. I had a horrible cold
A. terrible B. great C. nice D. common
e. The of flu include a headache, a high temperature and aches in the body.
A. symptom B. symptoms C. cure D. cures

Awall of 0.5m thickness is to be constructed from a material which has average thermal conductivity of 1.4 w/mk. the wall is to be insulated with a material having an average thermal conductivity of 0.35 w/mk so that heat loss per square meter shall not exceed 1450 w. assume inner wall surface temperature of 1200°c and outer surface temperature of the insulation to be 15°c. calculate the thickness of insulation required.