将一个正方形对折成两个长方形，每个长方形的长一定是它的宽的2倍。[ ]
正确
—Jack really likes reading.
—Yes, he goes to the library nearly once day, which is really surprise to me.
A．a; a
B．the; the
C．a; the
D．the; a
用来配制盐水钻井液的处理剂的是（）。
A、NaCl
B、CaCl2
C、BaS04
D、CaCO3
