胚胎干细胞的特点是（ ）
A：在形态上，表现为体积大，细胞核大，核仁明显；在功能上具有发育的全能性
B：在形态上，表现为体积小，细胞核大，核仁明显；在功能上具有发育的全能性
C：在形态上，表现为体积小，细胞核小，核仁不明显：在功能上不具有发育的全能性
D：在形态上，表现为体积大，细胞核小，核仁明显；在功能上具有发育的全能性
下列现象中，属于人口增长过慢造成的是（ ）
You ______a teacher. I ______ a student. My sister ______a student, too.
一台电动机正常工作时线圈两端的电压为380V，线圈电阻为2Ω，通过线圈的电流为10A．这台电动机正常工作1s内消耗的电能为 ____ J，线圈内产生的热量为 ____ J．
下列有关人体内酶的叙述正确的是 ( )①都是有分泌功能的细胞产生的 ②有的从食物中获得，有的在体内转化而来 ③凡是活细胞都能产生酶 ④酶都是蛋白质 ⑤有的酶是蛋白质，有的酶是RNA ⑥酶在代谢中有多种功能⑦酶在代谢中起调控作用 ⑧酶只起催化作用。
阅读下面材料，从每题所给的A、B、C、D四个选项中选出最佳选项。
WANTED
Are you good at playing the piano? Do you have time to teach a 7yearold boy to play it after school? 50 yuan an hour (小时). If your answer is "Yes", call Chen Qi at 8263666!
English Club
Do you want to practise your English and make more friends? Just join us on every Friday afternoon after school and enjoy learning English. Please call Kate at 15106495582.
FOUND
I found a math book on the playground this afternoon. Whose is it? Come to Class 4, Grade 1 to get it back.
NOTICE
A teacher will(将要)give us a lesson on travelling to different countries. Go to the No. 1 School Hall at 13: 00 this Friday and enjoy the twohour (小时) lesson.
