急！！！谁能帮我翻译一下下面的医学英语，对我们很重要！

第四周（发生第10-13期） 头褶及尾褶的形成使胚体逐渐弯曲并进一步呈“C”形，神经管在体节出现处已闭合，第一、二、三、对腮弓相继出现，内耳的原基听窝也清晰可见。在胚胎副外侧表面出现小隆起，即上肢芽，此后，出现第四对腮弓和下肢芽，出现血管、血细胞。
第五周 （发生第14、15期）本周胚胎外形的变化与第四周的相比已较小，但此时头部的生长较之其它各部位快，主要由于脑的迅速发生使胚胎的头部显著增大，不久脸面与腹侧的心隆起相接触，第二腮弓向后生长越过第三四腮弓，形成以外胚层的凹陷，称作颈窦。随着手板的发生，上肢开始显示出区段变化。
第六周 （发生第16、17期） 肢芽已显示出更明显的区段变化。上肢芽更为明显，渐可辨认肘部和腕部。腮弓周围出现数个小隆起，这腮沟逐渐演变为外耳道，周围的小隆起则合并并逐渐变为外耳门，视网膜色素开始出现，使眼也变得更加明显。这时胚胎的头与胚胎的躯干相比显得大得多，头弯曲地位于心隆起之上，胚胎的躯干和颈开始变直，至第六周末，体节开始在腰骶部出现。
第三个月 第九周初胎儿的头部几占胎儿全长的二分之一，以后，胎儿身体生长加快，至第12周末，顶臀长增加了一倍以上。头部的生长速度则较胎儿其余部分相比，减慢了许多。胎儿的脸部增宽，二眼相距较大，耳的位置低。由于上下眼睑的并和，使结膜囊闭合。同时，胎儿的外生殖器逐渐分化。
第四个月 胎儿生长迅速，月末时头部相对地变小而腿部相对地变长，骨骼迅速骨化，皮肤薄，透明，呈深红色。
第五个月 胎儿生长速度开始减慢，下肢的长度已达到最后的相对比例，此时胎儿的活动通常已能被母亲感觉出来，称为胎动。皮肤表面开始覆盖胎脂，可保护胎儿皮肤，在月末头与体表出现胎毛，还可见眉毛和头发，棕色脂肪也在此时形成。可以听见胎心音。

Head and tail of fold formed gradually to bend and further embryo body is "C", where has appeared in measurements neural tube closed, 1, 2, 3, to bow, the inner ear or one of the nest also hear clearly visible. In the embryo vice outside surface, small uplift, then shoots, upper and lower limbs of the fourth or bow shoots, vessels, cells.
The fifth week (first week 14, 15) with the changes of embryonic form of smaller than has been around, but now the head of each part of the fast growth compared with other mainly because of the brain, the embryo rapidly increased significantly to the head, soon to ventral heart uplift, the second phase contact or bow backward growth over the third bow, forming four gills outside the sag, called PeiCeng carotid sinus. With the upper hand, start showing section of change.
6 weeks in the 16th and 17th (first) limb buds have been shown to the section is more obvious changes. Upper buds and recognizable more obvious elbows and wrist. Gills bow occur around several small uplift, it has evolved into a ditch cheeks, demodectic pruritus small uplift while around and gradually become WaiErMen retinal pigment, began to appear, make eye has become more and more obvious. Then the head and the embryo of embryonic body is much larger than that in the head bent status, the embryo heart uplift trunk and neck began to grow straight to the sixth weekend, measurements of compre ion in the waist.
Article 9 months early fetal head of the fetus is a half of fetal body, and later, to the hips, long weekend more than doubled. The head of the growth rate is more than the rest of the fetus, slowing down a lot. The fetal face, eye apart by ear, low position. Because of eyelid, conjunctival sac and closed. At the same time, the fetal external genitalia gradually differentiation.
The first four months of fetal rapid growth, end relatively small head and legs are relatively longer, bone rapidly GuHua, skin, transparent, deep red.
The fifth month fetus began slowing growth speed, the length of the lower extremities has reached the final of the fetus ratio, usually can be mother felt, called quickened. The skin surface lipids, covering tire begin to protect fetus skin, head and at the end, there appeared TaiMao eyebrows and hair, brown fat is in this form. Sound can be heard TaiXin.

The fourth week (10-13 occurred in the first period) in the first fold and fold the end of the formation of the embryo so that the body was gradually bending further and "C"-shaped, neural tube section appears in the body have been closed, 1, 2, 3, branchial arch One after another, listen to the inner ear primordium Waterloo also clearly visible. Vice embryos in the outer surface of small bulge, that is, the upper limb bud, since the emergence of the fourth branchial arch and lower limb bud, the emergence of blood vessels, blood cells.
Fifth week (14, 15 occurred in the first period) this week and changes in the embryonic form of the fourth week has been compared to the smaller, but this time the head of growth than other parts of the fast, mainly due to the rapid brain so that the occurrence of embryos A significant increase in the head, face in the near future and uplift the hearts of the ventral contact, the second branchial arch backward over the growth of the third branchial arch, so as to form a tumor of the Depression, called the carotid sinus. With the occurrence of hand, the upper section of the show began to change.
Sixth week (16, 17 occurred in the first period) limb bud has shown more obvious changes in the section. More obvious upper limb bud, becoming recognizable elbow and wrist. Branchial arch around a number of small bulge, which gradually developed into a ditch gills external ear canal, around a small bulge and then gradually merged into outer doors, the beginning of retinal pigment, so that the eye becomes more apparent. At this time the embryo with the head of the embryonic body appears to be much larger compared to the first bend is located in the heart to swell above the neck and torso of the embryos began to change directly to the sixth week, the body section at the beginning of lumbosacral occur.
The first three months of the ninth week of fetal head and almost half the length of the fetus, after the fetal growth accelerated to 12 over the weekend, top-rump length more than doubled. The head of the growth rate than the rest of the fetus, slowed down a lot. The fetal face widened, 2 away from large, low ear position. Since the upper and lower eyelids and also so that the closed-sac. At the same time, the fetal genitalia gradually differentiation.
The first four months of the rapid growth of the fetus, at the end of the head when the relatively smaller and relatively longer legs, rapid bone ossification, skin thin, transparent, was dark red.
The first five months of fetal growth began to slow down the pace, the length of the lower limbs has reached the final of the relative proportion of the fetus at this time of the activities of the mother can usually feel, known as fetal movement. The surface of the skin covering the beginning of fetal fat, the protection of fetal skin, head and body surface appear at the end of lanugo, but also can be seen eyebrows and hair, brown fat is also formed at this time. Fetal heart rate can hear the sound.