Improperly implemented, dials can be extremely difficult to manipulate.

如果设计不当，刻度盘将会非常难于操作。

youdao

Unfortunately, they are also typically quite frustrating, difficult to manipulate, and wasteful of pixels.

遗憾，它通常也 很 令人沮丧，难于操作，而且浪费像素。

youdao

During this time the size of the embryo does not increase, so the cells become smaller and smaller and they are strongly attached to each other which makes them more difficult to manipulate.

在这段时间内胚胎的大小并未增加，因此细胞体积越来越小且彼此间连接紧密，导致较难对细胞进行操作。

youdao

During their test drive, the team at Trusted Reviews found the device to work quite well -- mostly due to its 2, 000dpi laser sensor -- although they thought that the top-mounted buttons were somewhat difficult to access, and joystick mode can't be used to manipulate the Z-axis.

ENGADGET: Fanatec Head$h0t gaming mouse reviewed