昨天的答案：

1. f   2. e   3. d   4. a   5. h   6. g   7. b   8. c

今天将学习ORTHO和RECT两个词根。

ORTHO. 源自希腊词语orthos, 意为"straight,""right,"或"true." Orthotics is a branch of therapy that straightens out your stance or posture by providing artificial support for weak joints or muscles. And orthograde animals, such as human beings, walk with their bodies in a "straight" or vertical position.

orthodontics. A branch of dentistry that deals with the treatment and correction of crooked teeth and other irregularities. 

例句：A specialty in orthodontics would require three more years of study after completing her dentistry degree.

Orthodontics has been practiced since ancient times, but the elaborate techniques familiar to us today were introduced only in recent decades. Braces, retainers, and headgear are used to fix such conditions as crowding of the teeth and overbites. According to a 1939 text, "Speech defects, psychiatric disturbances, personality changes, ... all are correctable through orthodontic measures," though many adolescents, having endured the embarrassment of rubber bands breaking and even of entangling their braces while kissing, might disagree.

orthodox. (1) Holding established beliefs, especially in religion. (2) Conforming to established rules or traditions; conventional.

例句：The O'Briens remain orthodox Catholics, faithfully observing the time-hornored rituals of their church.

An orthodox religious belief or interpretation is one handed down by a church's founders or leaders. When capitalized, as in Orthodox Judaism, Orthodox refers to a branch within a larger religious organization that claims to honor the religion's original or traditional beliefs. The steadfast holding of established beliefs that is seen in religious orthodoxy is apparent also in other kinds of orthodox behavior. Orthodox medical treatment, for example, follows the established practices of mainstream medicine. Unorthodox thinking is known in business language as "thinking outside the box."

orthopedics. The correction or prevention deformities(畸变) of the skeleton.

例句：For surgery to correct the child's spinal curvature, they were referred to the hospital's orthopedics section.

Just as an orthodontist corrects crookedness in the teeth, an orthopedist corrects crookedness in the skeleton. Orthopedics is formed in part from the Greek word for "child," and many orthopedic patients are in fact children.But adults also often have need of orthopedic therapy, as when suffering from a joint disease like arthritis or when recovering from a broken arm or leg.

orthography. The spelling of words, especially spelling according to standard usage.

例句：Even such eloquent writers as George Washington and Thomas Jefferson were deficient in the skill of of orthography.

Even as recently as the 19th century, the orthography of the English language was still unsettled. Not until spelling books like Noah Webster's and textbooks like "McGuffey's Readers" came along did uniform spelling become established in the U.S. Before that, there was much orthographic variation, even among the more educated. The many people who still have problems with spelling can take heart from Mark Twain, who once remarked, "I don't give a damn for a man that can spell a word only one way."

RECT. 源自拉丁词语rectus, 意为“straight"或"right." To correct something is to make it right. A rectangle is a four-sided figure with straight parallel sides. Rectus, short for Latin rectus musculus, may refer to any of several straight muscles, such as those of the abdomen.

rectitude. Moral integrity.

例句：The school superintendent was stern and not terribly popular, but no one questioned her moral rectitude.

We associate straightness with honesty, so if we suspect someone is lying we might ask if they're being "straight" with us, and we might call a lawbreaker crooked or label him a crook(骗子，罪犯), Rectitude may sound a little old-fashioned today, but the virtue it represents never really goes out of style.

rectify. To set right; remedy.

例句：The college is moving to rectify this unfortunate situation before anyone else gets hurt.

We rectify something by straightening it out or making it right. We might rectify an injustice by seeing to it that a wrongly accused person is cleared. An error in a financial record can be rectified by replacing an incorrect number with a correct one. If the error is in our tax return, the Internal Revenue Service will be happy to rectify it for us; we might then have to rectify the impression that we were trying to cheat on our taxes.

Rectilinear. (1) Moving in or forming a straight line. (2) Having many straight lines.

例句：After admiring Frank Lloyd Wright's rectilinear buildings for years, the public was astonished by the giant spiral of the Guggenheim Museum. 

Rectilinear patterns or constructions are those in which straight lines are strikingly obvious. In geometry, rectilinear usually means "perpendicular"; thus, a rectilinear polygon is a many-sided shape whose angles are all right angles (the footprints of most houses, with their extensions and garages, are good examples). But rectilinear is particularly used in physics. Rectilinear motion is motion in which the speed constant and the path is a straight line; and rectilinear rays, such as light rays, travel in a straight line.

directive. Something that guides or directs; especially, a general instruction from a high-level body or official.

例句：At the very beginning of the administration, the cabinet secretary had sent out a directive to all border-patrol personnel.

As the definition states, a directive directs. A directive from a school principal might provide guidance about handling holiday celebrations in class. A directive from the Vatican might specify new wording for the Mass in various languages. Even the European Union issues directives to its member countries, which they often ignore.

Quiz:

Choose the closest definition:

1. orthodox      a. straight   b. pier   c. conventional   d. waterfowl

2. rectify      a. redo   b. make right   c. modify   d. make longer

3. orthopedics      a. foot surgery   b. children's medicine   c. medical dictionaries   d. treatment of skeletal defects

4. directive      a. leader   b. sign   c. order   d. straighterner

5. orthography      a. correct color   b. correct map   c. correct direction   d. correct spelling

6. rectitude      a. roughness   b. integrity   c. certainty   d. sameness

7. orthodontics      a. dentistry for children   b. dentistry for gums   c. dentistry for crooked teeth   d. dentistry for everyone

8. rectilinear      a. employing straight lines   b. employing curved lines   c. employing 45° angles   d. emplying circles