Hiđrat hóa 2 anken chỉ tạo thành 2 ancol (rượu). Hai anken đó là

A. 2-metylpropen và but-1-en (hoặc buten-1).

B. propen và but-2-en (hoặc buten-2).

C. eten và but-2-en (hoặc buten-2).

D. eten và but-1-en (hoặc buten-1).

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. 

          Successful students often do the followings while studying. First they have an overview before reading. Next, they look for important information and pay greater attention to it (which often needs jumping forward or backward to process information). They also relate important points to one another. Also, they activate and use their prior knowledge. When they realize that their understanding is not good, they do not wait to change strategies. Last, they can monitor understanding and take action to correct or “ fix-up” mistakes in comprehension.

          Conversely, students with low academic achievement often demonstrate ineffective study skills. They tend to assume a passive role in learning and rely on others(e.g, teachers, parents) to monitor their studying. For example, low-achieving students often do not monitor their understanding of content, they may not be aware of the purpose of studying, and their show little evidence of looking back, or employing “fix-up” strategies to fix understanding problems. Students who struggle with learning new information seem to be unaware that they must extent beyond simply reading the content to understand and remember it. Children with learning disabilities do not plan and judge the quality off their studying. Their studying may be disorganized. Students with learning problems face challenges with personal organization as well. They often have difficulty keeping track of materials and assignments, following directions, and completing work on time. Unlike good student who employ a variety of study skills in a flexible yet purposeful manner, low-achieving students use a restricted range of skills. They can not explain why good study strategies are important for learning, and they tend to use the same, often ineffective, study approach for all learning tasks, ignoring task content, structure of difficulty.

In compared with low-achieving students, successful students use________.

A. inflexible study ways

B. various study skills

C. restricted strategies

D. aimless studying techniques