[单选题]交联聚乙烯电缆接头和终端用的应力控制管或应力控制带,是用介电常数大于( )高介电常数材料制成的。
A.5
B.10
C.20
D.30。

某房地产开发公司，具有建筑资质，2014年8月份发生如下业务：
（1）销售自建商品房一栋，取得销售收入2000万元。（工程成本460万元，成本利润率10%）
（2）转让已进入建筑物施工阶段的在建项目，取得收入500万元。
（3）销售已使用过的办公楼，取得收入854.6万元，该办公楼自建后，最初入账原值500万元，已提折旧200万元。
（4）将3年前购置的写字楼转让，取得转让款1500万元，该写字楼购置价为800万元，转让环节支付相关税费20万元。
（5）与甲企业签订合作经营协议，自8月起以度假村内价值2000万元的房产使用权与甲企业合作经营景区酒店（房屋产权仍属公司所有），约定每月租金为120万元，本月收到3个月的租金360万元。
（6）自建2栋同规格商品房，工程成本580万元/栋，将其中一栋自用；将另一栋赠送给合作单位，当月办理完产权转移手续，税务机关核定该栋商品房价值870万元。（当地规定成本利润率为10%）
（7）当月购买了两台税控收款机，一台取得专用发票，注明税额800元，一台取得普通发票，注明价款5850元。
要求：根据上述资料，回答下列问题：

Dear Sirs,
This is the third month running that your delivery has been late in arriving. Our current order for stationery is already five days overdue.
We have a number of valued customers who are being put to some inconvenience. There seems to be no obvious reason why your normally prompt deliveries should become so unreliable. I would be obliged if you would look into this matter as soon as possible.
Ours is a small, family business in a very parochial (狭小的) area. We depend very much upon the good will of our customers. I’ m sure you will appreciate the importance of this matter being cleared up at your easiest convenience.
Yours faithfully,
Grayson Brown
1) Mr. Brown writes to complain about (46) of the ordered goods.
2)His order for stationery has already been late for (47) when this letter is being written.
3) Mr. Brown feels it a pity that the (48) deliveries have become so un