20. (A) quandary (B) rhythm (C) ups and downs (D) obstacle

2. The list of present damages outlined by the United Nations panel — melting ice caps and rising sea levels, stressed water supplies, heat waves and heavy rains — the risk if humanity does not figure out how to curb the use of fossil fuels that have provided the lifeblood for economic development. (A) deteriorated (B) abolished (C) underscored (D) compressed