Science Review of the Ocean Floor

Overview Although much of the area of the ocean floor is unexplored, scientists have been able to find features that are common to all areas. The landforms that make up the ocean floor are different from those that make up the continents. A huge mountain range called the Mid-Oceanic Ridge divides sections of the oceans, […]

Science Review of X-Ray Astronomy

Overview Astronomers have discovered many high-energy objects in the sky that give off X-rays. Since the atmosphere blocks most X-rays from reaching observatories on Earth, astronomers have used telescopes from high-altitude balloons, rockets, and satellites to observe thousands of sources. X-Ray Sources X rays are part of the electromagnetic spectrum in high energy ranges beyond […]

English Review of Comma Errors

Overview Commas separate parts of a sentence grammatically, as well as separate items in a series. Without commas separating clauses, some of the meaning can be changed or lost. Commas in Series Use commas to separate each word, clause, or phrase in a series of three or more. For example, “She bought bread, milk, eggs, […]

English Review of Pronoun Errors

Overview Some common types of pronoun errors include pronoun agreement, pronoun ambiguity, pronoun shifts, and pronoun case. Those errors affect clarity of expression. Pronoun Agreement Pronouns should agree in number, person, and gender with the noun or noun phrase to which they refer. A singular pronoun refers back to a singular noun and a plural […]

Math Review of Linear Functions

Overview In order for functions to be linear, they must follow two criteria. First, each domain value must be paired with one range value. If a domain value is paired with more than one range value, the relationship is not a function. Second, the paired domain and range values must fall on a line to […]

Math Review of Arithmetic Sequences

Overview Arithmetic sequences are sequences in which the difference between one term and the next term is a constant amount. They can be defined by developing a rule that relates that constant to the pattern. Finding the Pattern The first step in determining the sequence is to arrange the terms in order. Suppose there is […]

Science Review of Baseball

Overview Baseball is a fast-paced sport that combines hitting, pitching, strategy, and timing. Some of the underlying scientific concepts include the aerodynamics of the baseball itself, the physics behind the collisions of the bat and ball, and the structure of the bat. Baseball Aerodynamics When a baseball is thrown, it follows a trajectory that starts […]

Science Review of Pendulums

Overview The simplest pendulum consists of a weight called a bob suspended from a pivot, allowed to swing freely. Its regular motion illustrates the relationship between gravity and tension. For centuries, pendulums were used in timekeeping and measurement. Motion of a Pendulum Suppose a solid pendulum bob is suspended from a cord attached to a […]

English Review of Kinds of Sentence Fragments

Overview Sentence fragments are writing errors in which a part of a sentence is punctuated as a complete sentence, with a capital letter at the beginning and closing punctuation at the end. However, a sentence fragment may lack a verb, a subject, may only have a verbal noun, or may only be a subordinate clause. […]

English Review of Types of Sentences

Overview Varying the types of sentences used within paragraphs can lead to effective writing. Some types of sentences include the simple sentence, the compound sentence, the complex sentence, and the compound-complex sentence. The Simple Sentence The simple sentence contains one independent clause. It can be as brief as a subject and verb, such as “Birds […]