热风焊接机主要用来焊接聚氯乙烯防水卷材平面的直线搭接缝。( )
参考答案：对
-- Is it necessary that he ____ to London but to New York?
-- I think so, but the problem is ____ he has refused to.
A．will not be sent; that
B．not be sent; that
C．should not be sent; what
D．should not sent; what
下列疾病中，不属于肿瘤的是（）。
A.上皮细胞瘤
B.血管瘤
C.嫌色细胞癌
D.动脉瘤
E.脂肪瘤
