In 1915, amateur astronomer George Willis Ritchey designed a new type of reflecting telescope that utilized a hyperbolic primary mirror. This innovative configuration ______ eliminated the optical aberration known as coma, which had long plagued traditional Newtonian reflectors and limited the clarity of deep-sky astrophotography. Today, nearly all major research installations, including the Hubble Space Telescope, rely on this design to capture high-resolution images of distant galaxies.
Which choice completes the text so that it conforms to the conventions of Standard English?
- A—a design later refined by French astronomer Henri Chrétien and known as the Ritchey-Chrétien telescope,
- —a design later refined by French astronomer Henri Chrétien and known as the Ritchey-Chrétien telescope—Cevap
- C, a design later refined by French astronomer Henri Chrétien and known as the Ritchey-Chrétien telescope—
- D, a design later refined by French astronomer Henri Chrétien and known as the Ritchey-Chrétien telescope
Cevap
The correct choice is the option that sets off the nonessential appositive phrase with a matching pair of em dashes.
The correct choice uses matching em dashes at both the beginning and the end of the nonessential appositive phrase. This maintains punctuation symmetry and grammatically isolates the descriptive details from the main independent clause.
Adım Adım Çözüm
Anahtar Kavram
Nonessential elements (such as appositives, parenthetical phrases, or nonrestrictive clauses) must be set off from the rest of the sentence using matching punctuation marks on both sides. Mixing punctuation marks (e.g., starting with a comma and ending with a dash) is grammatically incorrect.
Tahmini Süre:1m 0s