Problem: Adolescents' thinking is less bound to concrete events than that of children: they can contemplate possibilities outside the realm of what currently exists. One manifestation of the adolescent's increased facility with thinking about possibilities is the improvement of skill in deductive reasoning, which leads to the development of hypothetical thinking. This provides the ability to plan ahead, see the future consequences of an action and to provide alternative explanations of events. It also makes adolescents more skilled debaters, as they can reason against a friend's or parent's assumptions. Adolescents also develop a more sophisticated understanding of probability.
What type of thinking provides the ability to plan ahead and makes adolescents more skilled debaters?
The answer is the following: hypothetical

Problem: Water splitting, in which water is decomposed into its component protons, electrons, and oxygen, occurs in the light reactions in all photosynthetic organisms. Some such organisms, including the alga Chlamydomonas reinhardtii and cyanobacteria, have evolved a second step in the dark reactions in which protons and electrons are reduced to form H2 gas by specialized hydrogenases in the chloroplast. Efforts have been undertaken to genetically modify cyanobacterial hydrogenases to efficiently synthesize H2 gas even in the presence of oxygen. Efforts have also been undertaken with genetically modified alga in a bioreactor.
What organisms can form H2 gas?
The answer is the following: alga Chlamydomonas reinhardtii and cyanobacteria

Problem: Executive vice governor Wei Hong confirmed on November 21, 2008 that more than 90,000 people in total were dead or missing in the earthquake. He stated that 200,000 homes had been rebuilt, and 685,000 were under reconstruction, but 1.94 million households were still without permanent shelter. 1,300 schools had been reconstructed, with initial relocation of 25 townships, including Beichuan and Wenchuan, two of the most devastated areas. The government spent $441 billion on relief and reconstruction efforts.
How many families were still without permanent homes?
The answer is the following: 1.94 million

Problem: In 1936, Wever was killed in an air crash. The failure to implement his vision for the new Luftwaffe was largely attributable to his immediate successors. Ex-Army personnel Albert Kesselring and Hans-Jürgen Stumpff are usually blamed for the turning away from strategic planning and focusing on close air support. However, it would seem the two most prominent enthusiasts for the focus on ground-support operations (direct or indirect) were actually Hugo Sperrle and Hans Jeschonnek. These men were long-time professional airmen involved in German air services since early in their careers. The Luftwaffe was not pressured into ground support operations because of pressure from the army, or because it was led by ex-army personnel. It was instead a mission that suited the Luftwaffe's existing approach to warfare; a culture of joint inter-service operations, rather than independent strategic air campaigns.
What two men were the most important in ground support?
The answer is the following:
Hugo Sperrle and Hans Jeschonnek