妊娠时，B超检查探及胎动、胎心搏动是在
A．妊娠6周B．妊娠40天C．妊娠35天D．妊娠2月E．妊娠3月后
参考答案：E
With the world changing fast, we have something new ________(deal) with all by ourselves every day.
十字头销在检修中应注意什么？
