279. _______ not as bright as Venus, but it shines all night long.
a. Jupiter
b. Jupiter is
c. Jupiter being
d. On Jupiter

280. _______ when light is blocked.
a. Shadows form
b. The form of shadows
c. Shadows forming
d. Within the form of shadows

281. Alexander Graham Bell _______ deaf pupils in Boston in 1871, and he started work on the telephone three years later.
a. he began teaching
b. a beginning teacher
c. teaching beginning
d. began teaching

282. _______ have long life spans, many trees do not.
a. Some trees
b. Some are trees
c. Though some trees
d. Though some are trees

283. Gold can be found loose in nuggets, _______ can be trapped within veins of rock.
a. or it
b. it
c. its
d. or its

284. Eaglets are tended _____ they are 12 weeks old.
a. by both parents until
b. by both parents
c. both parents are
d. both parents

285. Bamboo is generally a tropical plant, but _____ in temperate zones.
a. can also be grown
b. also able to grow
c. it can also be grown
d. its ability to grow

286. While birds and mammals are warm-blooded, _____.
a. cold-blooded reptiles
b. reptiles are cold-blooded
c. but reptiles are cold-blooded
d. and cold-blooded reptiles

287. The retina is curved, so the image formed on the retina _____.
a. also curving
b. the additional curve
c. is also curved
d. it is also curved

288. Because Mars _____ on its axis, it has seasons like the Earth’s.
a. also tilting
b. the tilt of
c. with its tilt
d. is also tilted

289. Arteries carry blood away from the heart, _____ carry blood toward the heart.
a. veins
b. in veins
c. and veins
d. through veins

290. Although the silkworm is called a worm, _____ a caterpillar rather than worm.
a. really
b. it is really
c. is really
d. but it really is

291. _____ be composed of stone, or they may consist of an alloy of nickel and iron.
a. Meteorites may
b. Meteorites
c. In meteorites
d. For meteorites to

292. _____ can be exploded by a sound wave if the frequency of the sound wave matches the natural frequency of the glass.
a. Because a wineglass
b. The glass is for wine
c. In the glass for wine
d. A wineglass

293. Pasteurization of milk destroys any tuberculosis bacteria, _____ may remain.
a. other bacteria
b. but other bacteria
c. but in other bacteria
d. but other bacteria have

294. Jesse James once refused to rob a bank in McKenney, Texas, _____ was located in that town.
a. his favorite restaurant
b. at his favorite restaurant
c. because the restaurant was his favorite
d. since his favorite restaurant

295. The cells for other colors have not yet developed, so _____ are blue-eyed.
a. the babies are new born
b. most newborn babies
c. in most newborn babies
d. have most newborn babies

296. _____ off the ionosphere layer of the atmosphere as some radio signals are.
a. No bouncing microwave signals
b. Not to bounce microwave signals
c. Microwave signals are not bounced
d. Microwave signals not bouncing

297. A stork _____ developed larynx, or vocal organ, so it has no voice.
a. lacks a fully
b. fully lacking
c. the full lack
d. a full lack of

298. Siamese cats first appeared in Britain after the King of Siam _____ to the English consul general to take back to London.
a. presenting two cats
b. two cats were presented
c. the presentation of two cats
d. presented two cats