下列有关胎盘型ALP的叙述中错误的是（）

A.是ALP的同工酶

B.怀孕妇女血清中浓度升高

C.属于胚胎发育期的肿瘤标志物

D.升高见于各种癌症

E.在正常人中仅有较低浓度

请你用所给词的适当形式完成下列句子。

1. Here are some things they have learned from              (scientist ) studies.

2. Sunglasses are used for              (keep) out the sun.

3. The students are               (confuse) about the              (confuse) problem.

4. I'm considering               (study) in Beijing or Shanghai.

5. I felt               (embarrass) when everyone looked at me.