We couldn't start our journey. All flights _____ because of fog

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in the following questions. 

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions

Ha Tinh is a disaster-prone province in the central of Viet Nam. Since the beginning of 2015, this province has experienced three massive floods, causing devastating property damage. The floods razed thousands of homes, damaged numerous irrigation works, roads, schools and healthcare centres. Ms. Nga Tran, a local resident, recalled the last flood, “The flood in June was normal, but the one in September was awful. Water from Ngan Pho River began to submerge the floor, while outside it was still raining heavily. After a while the water was about one meter. I had no choice but to climb up to the attic and stay there for two days." Like many other residents, all of Ms Nga's furniture was covered in mud, some was completely damaged for having been soaked in the water for too long. But what worried her most was the loss of her rice crop. Three months after the flood, lots of farmers still struggled with finding enough food to eat. If there is no aid from the government, the situation in this province will get worse.

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word for each of the blanks

Are you looking for a cheap, clean, (38).....source of power that doesn't cause pollution or waste natural resources? Look no further than solar (39) ............from the sun.

At present, most of our (40).........comes from the use of coal and gas, oil, or (41).......power. This power could be provided by the sun. One percent of the solar energy that reaches the earth is enough to provide (42)............ for the total population.