读图回答问题。
地壳的上层F是（）层，下层G是（）层，F层与G层密度的比较是F（）G（填“>”、“<”或“=”）。
参考答案：
硅铝层；硅镁层；
— You didn't go to school yesterday, did you?
— , though there was a heavy rain. [ ]
A. Yes, I did
B. No, I didn't
C. Yes, I didn't
D. No, I did
对甲亢危象、重症甲亢列为首选的药是（）
A.甲硫氧嘧啶
B.丙硫氧嘧啶
C.卡比马唑
D.131I
E.甲巯咪唑
