Nhận biết (M1)

Although P/2019 LD2 (Atlas) and 121725 Aphidas are both classified as centaur objects—outer solar system bodies in unstable orbits—they exhibit striking differences in __________ object P/2019 LD2 (Atlas) is considered an active centaur, showing sporadic comet-like activity (such as clouds of dust and gas on its surface), 121725 Aphidas, showing no such activity, is considered dormant.

Which choice completes the text so that it conforms to the conventions of Standard English?

• A.

  behavior. The

• B.

  behavior, while the

• C.

  behavior; the

• D.

  behavior; while the